(* Title : Real.ML
Author : Jacques D. Fleuriot
Copyright : 1998 University of Cambridge
Description : The reals
*)
(*** Proving that realrel is an equivalence relation ***)
Goal "[| (x1::preal) + y2 = x2 + y1; x2 + y3 = x3 + y2 |] \
\ ==> x1 + y3 = x3 + y1";
by (res_inst_tac [("C","y2")] preal_add_right_cancel 1);
by (rotate_tac 1 1 THEN dtac sym 1);
by (asm_full_simp_tac (simpset() addsimps preal_add_ac) 1);
by (rtac (preal_add_left_commute RS subst) 1);
by (res_inst_tac [("x1","x1")] (preal_add_assoc RS subst) 1);
by (asm_full_simp_tac (simpset() addsimps preal_add_ac) 1);
qed "preal_trans_lemma";
(** Natural deduction for realrel **)
Goalw [realrel_def]
"(((x1,y1),(x2,y2)): realrel) = (x1 + y2 = x2 + y1)";
by (Blast_tac 1);
qed "realrel_iff";
Goalw [realrel_def]
"[| x1 + y2 = x2 + y1 |] ==> ((x1,y1),(x2,y2)): realrel";
by (Blast_tac 1);
qed "realrelI";
Goalw [realrel_def]
"p: realrel --> (EX x1 y1 x2 y2. \
\ p = ((x1,y1),(x2,y2)) & x1 + y2 = x2 + y1)";
by (Blast_tac 1);
qed "realrelE_lemma";
val [major,minor] = goal thy
"[| p: realrel; \
\ !!x1 y1 x2 y2. [| p = ((x1,y1),(x2,y2)); x1+y2 = x2+y1 \
\ |] ==> Q |] ==> Q";
by (cut_facts_tac [major RS (realrelE_lemma RS mp)] 1);
by (REPEAT (eresolve_tac [asm_rl,exE,conjE,minor] 1));
qed "realrelE";
AddSIs [realrelI];
AddSEs [realrelE];
Goal "(x,x): realrel";
by (stac surjective_pairing 1 THEN rtac (refl RS realrelI) 1);
qed "realrel_refl";
Goalw [equiv_def, refl_def, sym_def, trans_def]
"equiv {x::(preal*preal).True} realrel";
by (fast_tac (claset() addSIs [realrel_refl]
addSEs [sym,preal_trans_lemma]) 1);
qed "equiv_realrel";
val equiv_realrel_iff =
[TrueI, TrueI] MRS
([CollectI, CollectI] MRS
(equiv_realrel RS eq_equiv_class_iff));
Goalw [real_def,realrel_def,quotient_def] "realrel^^{(x,y)}:real";
by (Blast_tac 1);
qed "realrel_in_real";
Goal "inj_on Abs_real real";
by (rtac inj_on_inverseI 1);
by (etac Abs_real_inverse 1);
qed "inj_on_Abs_real";
Addsimps [equiv_realrel_iff,inj_on_Abs_real RS inj_on_iff,
realrel_iff, realrel_in_real, Abs_real_inverse];
Addsimps [equiv_realrel RS eq_equiv_class_iff];
val eq_realrelD = equiv_realrel RSN (2,eq_equiv_class);
Goal "inj(Rep_real)";
by (rtac inj_inverseI 1);
by (rtac Rep_real_inverse 1);
qed "inj_Rep_real";
(** real_preal: the injection from preal to real **)
Goal "inj(real_preal)";
by (rtac injI 1);
by (rewtac real_preal_def);
by (dtac (inj_on_Abs_real RS inj_onD) 1);
by (REPEAT (rtac realrel_in_real 1));
by (dtac eq_equiv_class 1);
by (rtac equiv_realrel 1);
by (Blast_tac 1);
by Safe_tac;
by (Asm_full_simp_tac 1);
qed "inj_real_preal";
val [prem] = goal thy
"(!!x y. z = Abs_real(realrel^^{(x,y)}) ==> P) ==> P";
by (res_inst_tac [("x1","z")]
(rewrite_rule [real_def] Rep_real RS quotientE) 1);
by (dres_inst_tac [("f","Abs_real")] arg_cong 1);
by (res_inst_tac [("p","x")] PairE 1);
by (rtac prem 1);
by (asm_full_simp_tac (simpset() addsimps [Rep_real_inverse]) 1);
qed "eq_Abs_real";
(**** real_minus: additive inverse on real ****)
Goalw [congruent_def]
"congruent realrel (%p. split (%x y. realrel^^{(y,x)}) p)";
by Safe_tac;
by (asm_full_simp_tac (simpset() addsimps [preal_add_commute]) 1);
qed "real_minus_congruent";
(*Resolve th against the corresponding facts for real_minus*)
val real_minus_ize = RSLIST [equiv_realrel, real_minus_congruent];
Goalw [real_minus_def]
"%~ (Abs_real(realrel^^{(x,y)})) = Abs_real(realrel ^^ {(y,x)})";
by (res_inst_tac [("f","Abs_real")] arg_cong 1);
by (simp_tac (simpset() addsimps
[realrel_in_real RS Abs_real_inverse,real_minus_ize UN_equiv_class]) 1);
qed "real_minus";
Goal "%~ (%~ z) = z";
by (res_inst_tac [("z","z")] eq_Abs_real 1);
by (asm_simp_tac (simpset() addsimps [real_minus]) 1);
qed "real_minus_minus";
Addsimps [real_minus_minus];
Goal "inj(real_minus)";
by (rtac injI 1);
by (dres_inst_tac [("f","real_minus")] arg_cong 1);
by (asm_full_simp_tac (simpset() addsimps [real_minus_minus]) 1);
qed "inj_real_minus";
Goalw [real_zero_def] "%~0r = 0r";
by (simp_tac (simpset() addsimps [real_minus]) 1);
qed "real_minus_zero";
Addsimps [real_minus_zero];
Goal "(%~x = 0r) = (x = 0r)";
by (res_inst_tac [("z","x")] eq_Abs_real 1);
by (auto_tac (claset(),simpset() addsimps [real_zero_def,
real_minus] @ preal_add_ac));
qed "real_minus_zero_iff";
Addsimps [real_minus_zero_iff];
Goal "(%~x ~= 0r) = (x ~= 0r)";
by Auto_tac;
qed "real_minus_not_zero_iff";
(*** Congruence property for addition ***)
Goalw [congruent2_def]
"congruent2 realrel (%p1 p2. \
\ split (%x1 y1. split (%x2 y2. realrel^^{(x1+x2, y1+y2)}) p2) p1)";
by Safe_tac;
by (asm_simp_tac (simpset() addsimps [preal_add_assoc]) 1);
by (res_inst_tac [("z1.1","x1a")] (preal_add_left_commute RS ssubst) 1);
by (asm_simp_tac (simpset() addsimps [preal_add_assoc RS sym]) 1);
by (asm_simp_tac (simpset() addsimps preal_add_ac) 1);
qed "real_add_congruent2";
(*Resolve th against the corresponding facts for real_add*)
val real_add_ize = RSLIST [equiv_realrel, real_add_congruent2];
Goalw [real_add_def]
"Abs_real(realrel^^{(x1,y1)}) + Abs_real(realrel^^{(x2,y2)}) = \
\ Abs_real(realrel^^{(x1+x2, y1+y2)})";
by (asm_simp_tac
(simpset() addsimps [real_add_ize UN_equiv_class2]) 1);
qed "real_add";
Goal "(z::real) + w = w + z";
by (res_inst_tac [("z","z")] eq_Abs_real 1);
by (res_inst_tac [("z","w")] eq_Abs_real 1);
by (asm_simp_tac (simpset() addsimps preal_add_ac @ [real_add]) 1);
qed "real_add_commute";
Goal "((z1::real) + z2) + z3 = z1 + (z2 + z3)";
by (res_inst_tac [("z","z1")] eq_Abs_real 1);
by (res_inst_tac [("z","z2")] eq_Abs_real 1);
by (res_inst_tac [("z","z3")] eq_Abs_real 1);
by (asm_simp_tac (simpset() addsimps [real_add, preal_add_assoc]) 1);
qed "real_add_assoc";
(*For AC rewriting*)
Goal "(x::real)+(y+z)=y+(x+z)";
by (rtac (real_add_commute RS trans) 1);
by (rtac (real_add_assoc RS trans) 1);
by (rtac (real_add_commute RS arg_cong) 1);
qed "real_add_left_commute";
(* real addition is an AC operator *)
val real_add_ac = [real_add_assoc,real_add_commute,real_add_left_commute];
Goalw [real_preal_def,real_zero_def] "0r + z = z";
by (res_inst_tac [("z","z")] eq_Abs_real 1);
by (asm_full_simp_tac (simpset() addsimps [real_add] @ preal_add_ac) 1);
qed "real_add_zero_left";
Goal "z + 0r = z";
by (simp_tac (simpset() addsimps [real_add_zero_left,real_add_commute]) 1);
qed "real_add_zero_right";
Goalw [real_zero_def] "z + %~z = 0r";
by (res_inst_tac [("z","z")] eq_Abs_real 1);
by (asm_full_simp_tac (simpset() addsimps [real_minus,
real_add, preal_add_commute]) 1);
qed "real_add_minus";
Goal "%~z + z = 0r";
by (simp_tac (simpset() addsimps
[real_add_commute,real_add_minus]) 1);
qed "real_add_minus_left";
Goal "? y. (x::real) + y = 0r";
by (blast_tac (claset() addIs [real_add_minus]) 1);
qed "real_minus_ex";
Goal "?! y. (x::real) + y = 0r";
by (auto_tac (claset() addIs [real_add_minus],simpset()));
by (dres_inst_tac [("f","%x. ya+x")] arg_cong 1);
by (asm_full_simp_tac (simpset() addsimps [real_add_assoc RS sym]) 1);
by (asm_full_simp_tac (simpset() addsimps [real_add_commute,
real_add_zero_right,real_add_zero_left]) 1);
qed "real_minus_ex1";
Goal "?! y. y + (x::real) = 0r";
by (auto_tac (claset() addIs [real_add_minus_left],simpset()));
by (dres_inst_tac [("f","%x. x+ya")] arg_cong 1);
by (asm_full_simp_tac (simpset() addsimps [real_add_assoc]) 1);
by (asm_full_simp_tac (simpset() addsimps [real_add_commute,
real_add_zero_right,real_add_zero_left]) 1);
qed "real_minus_left_ex1";
Goal "x + y = 0r ==> x = %~y";
by (cut_inst_tac [("z","y")] real_add_minus_left 1);
by (res_inst_tac [("x1","y")] (real_minus_left_ex1 RS ex1E) 1);
by (Blast_tac 1);
qed "real_add_minus_eq_minus";
Goal "? y. x = %~y";
by (cut_inst_tac [("x","x")] real_minus_ex 1);
by (etac exE 1 THEN dtac real_add_minus_eq_minus 1);
by (Blast_tac 1);
qed "real_as_add_inverse_ex";
(* real_minus_add_distrib *)
Goal "%~(x + y) = %~x + %~y";
by (res_inst_tac [("z","x")] eq_Abs_real 1);
by (res_inst_tac [("z","y")] eq_Abs_real 1);
by (auto_tac (claset(),simpset() addsimps [real_minus,real_add]));
qed "real_minus_add_eq";
val real_minus_add_distrib = real_minus_add_eq;
Goal "((x::real) + y = x + z) = (y = z)";
by (Step_tac 1);
by (dres_inst_tac [("f","%t.%~x + t")] arg_cong 1);
by (asm_full_simp_tac (simpset() addsimps [real_add_minus_left,
real_add_assoc RS sym,real_add_zero_left]) 1);
qed "real_add_left_cancel";
Goal "(y + (x::real)= z + x) = (y = z)";
by (simp_tac (simpset() addsimps [real_add_commute,real_add_left_cancel]) 1);
qed "real_add_right_cancel";
(*** Congruence property for multiplication ***)
Goal "!!(x1::preal). [| x1 + y2 = x2 + y1 |] ==> \
\ x * x1 + y * y1 + (x * y2 + x2 * y) = \
\ x * x2 + y * y2 + (x * y1 + x1 * y)";
by (asm_full_simp_tac (simpset() addsimps [preal_add_left_commute,
preal_add_assoc RS sym,preal_add_mult_distrib2 RS sym]) 1);
by (rtac (preal_mult_commute RS subst) 1);
by (res_inst_tac [("y1","x2")] (preal_mult_commute RS subst) 1);
by (asm_full_simp_tac (simpset() addsimps [preal_add_assoc,
preal_add_mult_distrib2 RS sym]) 1);
by (asm_full_simp_tac (simpset() addsimps [preal_add_commute]) 1);
qed "real_mult_congruent2_lemma";
Goal
"congruent2 realrel (%p1 p2. \
\ split (%x1 y1. split (%x2 y2. realrel^^{(x1*x2 + y1*y2, x1*y2+x2*y1)}) p2) p1)";
by (rtac (equiv_realrel RS congruent2_commuteI) 1);
by Safe_tac;
by (rewtac split_def);
by (asm_simp_tac (simpset() addsimps [preal_mult_commute,preal_add_commute]) 1);
by (auto_tac (claset(),simpset() addsimps [real_mult_congruent2_lemma]));
qed "real_mult_congruent2";
(*Resolve th against the corresponding facts for real_mult*)
val real_mult_ize = RSLIST [equiv_realrel, real_mult_congruent2];
Goalw [real_mult_def]
"Abs_real((realrel^^{(x1,y1)})) * Abs_real((realrel^^{(x2,y2)})) = \
\ Abs_real(realrel ^^ {(x1*x2+y1*y2,x1*y2+x2*y1)})";
by (simp_tac (simpset() addsimps [real_mult_ize UN_equiv_class2]) 1);
qed "real_mult";
Goal "(z::real) * w = w * z";
by (res_inst_tac [("z","z")] eq_Abs_real 1);
by (res_inst_tac [("z","w")] eq_Abs_real 1);
by (asm_simp_tac
(simpset() addsimps [real_mult] @ preal_add_ac @ preal_mult_ac) 1);
qed "real_mult_commute";
Goal "((z1::real) * z2) * z3 = z1 * (z2 * z3)";
by (res_inst_tac [("z","z1")] eq_Abs_real 1);
by (res_inst_tac [("z","z2")] eq_Abs_real 1);
by (res_inst_tac [("z","z3")] eq_Abs_real 1);
by (asm_simp_tac (simpset() addsimps [preal_add_mult_distrib2,real_mult] @
preal_add_ac @ preal_mult_ac) 1);
qed "real_mult_assoc";
qed_goal "real_mult_left_commute" thy
"(z1::real) * (z2 * z3) = z2 * (z1 * z3)"
(fn _ => [rtac (real_mult_commute RS trans) 1, rtac (real_mult_assoc RS trans) 1,
rtac (real_mult_commute RS arg_cong) 1]);
(* real multiplication is an AC operator *)
val real_mult_ac = [real_mult_assoc, real_mult_commute, real_mult_left_commute];
Goalw [real_one_def,pnat_one_def] "1r * z = z";
by (res_inst_tac [("z","z")] eq_Abs_real 1);
by (asm_full_simp_tac (simpset() addsimps [real_mult,
preal_add_mult_distrib2,preal_mult_1_right]
@ preal_mult_ac @ preal_add_ac) 1);
qed "real_mult_1";
Goal "z * 1r = z";
by (simp_tac (simpset() addsimps [real_mult_commute,
real_mult_1]) 1);
qed "real_mult_1_right";
Goalw [real_zero_def,pnat_one_def] "0r * z = 0r";
by (res_inst_tac [("z","z")] eq_Abs_real 1);
by (asm_full_simp_tac (simpset() addsimps [real_mult,
preal_add_mult_distrib2,preal_mult_1_right]
@ preal_mult_ac @ preal_add_ac) 1);
qed "real_mult_0";
Goal "z * 0r = 0r";
by (simp_tac (simpset() addsimps [real_mult_commute,
real_mult_0]) 1);
qed "real_mult_0_right";
Addsimps [real_mult_0_right,real_mult_0];
Goal "%~(x * y) = %~x * y";
by (res_inst_tac [("z","x")] eq_Abs_real 1);
by (res_inst_tac [("z","y")] eq_Abs_real 1);
by (auto_tac (claset(),simpset() addsimps [real_minus,real_mult]
@ preal_mult_ac @ preal_add_ac));
qed "real_minus_mult_eq1";
Goal "%~(x * y) = x * %~y";
by (res_inst_tac [("z","x")] eq_Abs_real 1);
by (res_inst_tac [("z","y")] eq_Abs_real 1);
by (auto_tac (claset(),simpset() addsimps [real_minus,real_mult]
@ preal_mult_ac @ preal_add_ac));
qed "real_minus_mult_eq2";
Goal "%~x*%~y = x*y";
by (full_simp_tac (simpset() addsimps [real_minus_mult_eq2 RS sym,
real_minus_mult_eq1 RS sym]) 1);
qed "real_minus_mult_cancel";
Addsimps [real_minus_mult_cancel];
Goal "%~x*y = x*%~y";
by (full_simp_tac (simpset() addsimps [real_minus_mult_eq2 RS sym,
real_minus_mult_eq1 RS sym]) 1);
qed "real_minus_mult_commute";
(*-----------------------------------------------------------------------------
-----------------------------------------------------------------------------*)
(** Lemmas **)
qed_goal "real_add_assoc_cong" thy
"!!z. (z::real) + v = z' + v' ==> z + (v + w) = z' + (v' + w)"
(fn _ => [(asm_simp_tac (simpset() addsimps [real_add_assoc RS sym]) 1)]);
qed_goal "real_add_assoc_swap" thy "(z::real) + (v + w) = v + (z + w)"
(fn _ => [(REPEAT (ares_tac [real_add_commute RS real_add_assoc_cong] 1))]);
Goal "((z1::real) + z2) * w = (z1 * w) + (z2 * w)";
by (res_inst_tac [("z","z1")] eq_Abs_real 1);
by (res_inst_tac [("z","z2")] eq_Abs_real 1);
by (res_inst_tac [("z","w")] eq_Abs_real 1);
by (asm_simp_tac
(simpset() addsimps [preal_add_mult_distrib2, real_add, real_mult] @
preal_add_ac @ preal_mult_ac) 1);
qed "real_add_mult_distrib";
val real_mult_commute'= read_instantiate [("z","w")] real_mult_commute;
Goal "(w::real) * (z1 + z2) = (w * z1) + (w * z2)";
by (simp_tac (simpset() addsimps [real_mult_commute',real_add_mult_distrib]) 1);
qed "real_add_mult_distrib2";
val real_mult_simps = [real_mult_1, real_mult_1_right];
Addsimps real_mult_simps;
(*** one and zero are distinct ***)
Goalw [real_zero_def,real_one_def] "0r ~= 1r";
by (auto_tac (claset(),simpset() addsimps
[preal_self_less_add_left RS preal_not_refl2]));
qed "real_zero_not_eq_one";
(*** existence of inverse ***)
(** lemma -- alternative definition for 0r **)
Goalw [real_zero_def] "0r = Abs_real (realrel ^^ {(x, x)})";
by (auto_tac (claset(),simpset() addsimps [preal_add_commute]));
qed "real_zero_iff";
Goalw [real_zero_def,real_one_def]
"!!(x::real). x ~= 0r ==> ? y. x*y = 1r";
by (res_inst_tac [("z","x")] eq_Abs_real 1);
by (cut_inst_tac [("r1.0","xa"),("r2.0","y")] preal_linear 1);
by (auto_tac (claset() addSDs [preal_less_add_left_Ex],
simpset() addsimps [real_zero_iff RS sym]));
by (res_inst_tac [("x","Abs_real (realrel ^^ {(@#$#1p,pinv(D)+@#$#1p)})")] exI 1);
by (res_inst_tac [("x","Abs_real (realrel ^^ {(pinv(D)+@#$#1p,@#$#1p)})")] exI 2);
by (auto_tac (claset(),simpset() addsimps [real_mult,
pnat_one_def,preal_mult_1_right,preal_add_mult_distrib2,
preal_add_mult_distrib,preal_mult_1,preal_mult_inv_right]
@ preal_add_ac @ preal_mult_ac));
qed "real_mult_inv_right_ex";
Goal "!!(x::real). x ~= 0r ==> ? y. y*x = 1r";
by (asm_simp_tac (simpset() addsimps [real_mult_commute,
real_mult_inv_right_ex]) 1);
qed "real_mult_inv_left_ex";
Goalw [rinv_def] "!!(x::real). x ~= 0r ==> rinv(x)*x = 1r";
by (forward_tac [real_mult_inv_left_ex] 1);
by (Step_tac 1);
by (rtac selectI2 1);
by Auto_tac;
qed "real_mult_inv_left";
Goal "!!(x::real). x ~= 0r ==> x*rinv(x) = 1r";
by (auto_tac (claset() addIs [real_mult_commute RS subst],
simpset() addsimps [real_mult_inv_left]));
qed "real_mult_inv_right";
Goal "(c::real) ~= 0r ==> (c*a=c*b) = (a=b)";
by Auto_tac;
by (dres_inst_tac [("f","%x. x*rinv c")] arg_cong 1);
by (asm_full_simp_tac (simpset() addsimps [real_mult_inv_right] @ real_mult_ac) 1);
qed "real_mult_left_cancel";
Goal "(c::real) ~= 0r ==> (a*c=b*c) = (a=b)";
by (Step_tac 1);
by (dres_inst_tac [("f","%x. x*rinv c")] arg_cong 1);
by (asm_full_simp_tac (simpset() addsimps [real_mult_inv_right] @ real_mult_ac) 1);
qed "real_mult_right_cancel";
Goalw [rinv_def] "x ~= 0r ==> rinv(x) ~= 0r";
by (forward_tac [real_mult_inv_left_ex] 1);
by (etac exE 1);
by (rtac selectI2 1);
by (auto_tac (claset(),simpset() addsimps [real_mult_0,
real_zero_not_eq_one]));
qed "rinv_not_zero";
Addsimps [real_mult_inv_left,real_mult_inv_right];
Goal "x ~= 0r ==> rinv(rinv x) = x";
by (res_inst_tac [("c1","rinv x")] (real_mult_right_cancel RS iffD1) 1);
by (etac rinv_not_zero 1);
by (auto_tac (claset() addDs [rinv_not_zero],simpset()));
qed "real_rinv_rinv";
Goalw [rinv_def] "rinv(1r) = 1r";
by (cut_facts_tac [real_zero_not_eq_one RS
not_sym RS real_mult_inv_left_ex] 1);
by (etac exE 1);
by (rtac selectI2 1);
by (auto_tac (claset(),simpset() addsimps
[real_zero_not_eq_one RS not_sym]));
qed "real_rinv_1";
Goal "x ~= 0r ==> rinv(%~x) = %~rinv(x)";
by (res_inst_tac [("c1","%~x")] (real_mult_right_cancel RS iffD1) 1);
by Auto_tac;
qed "real_minus_rinv";
(*** theorems for ordering ***)
(* prove introduction and elimination rules for real_less *)
Goalw [real_less_def]
"P < (Q::real) = (EX x1 y1 x2 y2. x1 + y2 < x2 + y1 & \
\ (x1,y1::preal):Rep_real(P) & \
\ (x2,y2):Rep_real(Q))";
by (Blast_tac 1);
qed "real_less_iff";
Goalw [real_less_def]
"[| x1 + y2 < x2 + y1; (x1,y1::preal):Rep_real(P); \
\ (x2,y2):Rep_real(Q) |] ==> P < (Q::real)";
by (Blast_tac 1);
qed "real_lessI";
Goalw [real_less_def]
"!!P. [| R1 < (R2::real); \
\ !!x1 x2 y1 y2. x1 + y2 < x2 + y1 ==> P; \
\ !!x1 y1. (x1,y1::preal):Rep_real(R1) ==> P; \
\ !!x2 y2. (x2,y2::preal):Rep_real(R2) ==> P |] \
\ ==> P";
by Auto_tac;
qed "real_lessE";
Goalw [real_less_def]
"R1 < (R2::real) ==> (EX x1 y1 x2 y2. x1 + y2 < x2 + y1 & \
\ (x1,y1::preal):Rep_real(R1) & \
\ (x2,y2):Rep_real(R2))";
by (Blast_tac 1);
qed "real_lessD";
(* real_less is a strong order i.e nonreflexive and transitive *)
(*** lemmas ***)
Goal "!!(x::preal). [| x = y; x1 = y1 |] ==> x + y1 = x1 + y";
by (asm_simp_tac (simpset() addsimps [preal_add_commute]) 1);
qed "preal_lemma_eq_rev_sum";
Goal "!!(b::preal). x + (b + y) = x1 + (b + y1) ==> x + y = x1 + y1";
by (asm_full_simp_tac (simpset() addsimps preal_add_ac) 1);
qed "preal_add_left_commute_cancel";
Goal
"!!(x::preal). [| x + y2a = x2a + y; \
\ x + y2b = x2b + y |] \
\ ==> x2a + y2b = x2b + y2a";
by (dtac preal_lemma_eq_rev_sum 1);
by (assume_tac 1);
by (thin_tac "x + y2b = x2b + y" 1);
by (asm_full_simp_tac (simpset() addsimps preal_add_ac) 1);
by (dtac preal_add_left_commute_cancel 1);
by (asm_full_simp_tac (simpset() addsimps preal_add_ac) 1);
qed "preal_lemma_for_not_refl";
Goal "~ (R::real) < R";
by (res_inst_tac [("z","R")] eq_Abs_real 1);
by (auto_tac (claset(),simpset() addsimps [real_less_def]));
by (dtac preal_lemma_for_not_refl 1);
by (assume_tac 1 THEN rotate_tac 2 1);
by (auto_tac (claset(),simpset() addsimps [preal_less_not_refl]));
qed "real_less_not_refl";
(*** y < y ==> P ***)
bind_thm("real_less_irrefl",real_less_not_refl RS notE);
Goal "!!(x::real). x < y ==> x ~= y";
by (auto_tac (claset(),simpset() addsimps [real_less_not_refl]));
qed "real_not_refl2";
(* lemma re-arranging and eliminating terms *)
Goal "!! (a::preal). [| a + b = c + d; \
\ x2b + d + (c + y2e) < a + y2b + (x2e + b) |] \
\ ==> x2b + y2e < x2e + y2b";
by (asm_full_simp_tac (simpset() addsimps preal_add_ac) 1);
by (res_inst_tac [("C","c+d")] preal_add_left_less_cancel 1);
by (asm_full_simp_tac (simpset() addsimps [preal_add_assoc RS sym]) 1);
qed "preal_lemma_trans";
(** heavy re-writing involved*)
Goal "!!(R1::real). [| R1 < R2; R2 < R3 |] ==> R1 < R3";
by (res_inst_tac [("z","R1")] eq_Abs_real 1);
by (res_inst_tac [("z","R2")] eq_Abs_real 1);
by (res_inst_tac [("z","R3")] eq_Abs_real 1);
by (auto_tac (claset(),simpset() addsimps [real_less_def]));
by (REPEAT(rtac exI 1));
by (EVERY[rtac conjI 1, rtac conjI 2]);
by (REPEAT(Blast_tac 2));
by (dtac preal_lemma_for_not_refl 1 THEN assume_tac 1);
by (blast_tac (claset() addDs [preal_add_less_mono]
addIs [preal_lemma_trans]) 1);
qed "real_less_trans";
Goal "!! (R1::real). [| R1 < R2; R2 < R1 |] ==> P";
by (dtac real_less_trans 1 THEN assume_tac 1);
by (asm_full_simp_tac (simpset() addsimps [real_less_not_refl]) 1);
qed "real_less_asym";
(****)(****)(****)(****)(****)(****)(****)(****)(****)(****)
(****** Map and more real_less ******)
(*** mapping from preal into real ***)
Goalw [real_preal_def]
"%#((z1::preal) + z2) = %#z1 + %#z2";
by (asm_simp_tac (simpset() addsimps [real_add,
preal_add_mult_distrib,preal_mult_1] addsimps preal_add_ac) 1);
qed "real_preal_add";
Goalw [real_preal_def]
"%#((z1::preal) * z2) = %#z1* %#z2";
by (full_simp_tac (simpset() addsimps [real_mult,
preal_add_mult_distrib2,preal_mult_1,
preal_mult_1_right,pnat_one_def]
@ preal_add_ac @ preal_mult_ac) 1);
qed "real_preal_mult";
Goalw [real_preal_def]
"!!(x::preal). y < x ==> ? m. Abs_real (realrel ^^ {(x,y)}) = %#m";
by (auto_tac (claset() addSDs [preal_less_add_left_Ex],
simpset() addsimps preal_add_ac));
qed "real_preal_ExI";
Goalw [real_preal_def]
"!!(x::preal). ? m. Abs_real (realrel ^^ {(x,y)}) = %#m ==> y < x";
by (auto_tac (claset(),simpset() addsimps
[preal_add_commute,preal_add_assoc]));
by (asm_full_simp_tac (simpset() addsimps
[preal_add_assoc RS sym,preal_self_less_add_left]) 1);
qed "real_preal_ExD";
Goal "(? m. Abs_real (realrel ^^ {(x,y)}) = %#m) = (y < x)";
by (blast_tac (claset() addSIs [real_preal_ExI,real_preal_ExD]) 1);
qed "real_preal_iff";
(*** Gleason prop 9-4.4 p 127 ***)
Goalw [real_preal_def,real_zero_def]
"? m. (x::real) = %#m | x = 0r | x = %~(%#m)";
by (res_inst_tac [("z","x")] eq_Abs_real 1);
by (auto_tac (claset(),simpset() addsimps [real_minus] @ preal_add_ac));
by (cut_inst_tac [("r1.0","x"),("r2.0","y")] preal_linear 1);
by (auto_tac (claset() addSDs [preal_less_add_left_Ex],
simpset() addsimps [preal_add_assoc RS sym]));
by (auto_tac (claset(),simpset() addsimps [preal_add_commute]));
qed "real_preal_trichotomy";
Goal "!!P. [| !!m. x = %#m ==> P; \
\ x = 0r ==> P; \
\ !!m. x = %~(%#m) ==> P |] ==> P";
by (cut_inst_tac [("x","x")] real_preal_trichotomy 1);
by Auto_tac;
qed "real_preal_trichotomyE";
Goalw [real_preal_def] "%#m1 < %#m2 ==> m1 < m2";
by (auto_tac (claset(),simpset() addsimps [real_less_def] @ preal_add_ac));
by (auto_tac (claset(),simpset() addsimps [preal_add_assoc RS sym]));
by (auto_tac (claset(),simpset() addsimps preal_add_ac));
qed "real_preal_lessD";
Goal "m1 < m2 ==> %#m1 < %#m2";
by (dtac preal_less_add_left_Ex 1);
by (auto_tac (claset(),simpset() addsimps [real_preal_add,
real_preal_def,real_less_def]));
by (REPEAT(rtac exI 1));
by (EVERY[rtac conjI 1, rtac conjI 2]);
by (REPEAT(Blast_tac 2));
by (simp_tac (simpset() addsimps [preal_self_less_add_left]
delsimps [preal_add_less_iff2]) 1);
qed "real_preal_lessI";
Goal "(%#m1 < %#m2) = (m1 < m2)";
by (blast_tac (claset() addIs [real_preal_lessI,real_preal_lessD]) 1);
qed "real_preal_less_iff1";
Addsimps [real_preal_less_iff1];
Goal "%~ %#m < %#m";
by (auto_tac (claset(),simpset() addsimps
[real_preal_def,real_less_def,real_minus]));
by (REPEAT(rtac exI 1));
by (EVERY[rtac conjI 1, rtac conjI 2]);
by (REPEAT(Blast_tac 2));
by (full_simp_tac (simpset() addsimps preal_add_ac) 1);
by (full_simp_tac (simpset() addsimps [preal_self_less_add_right,
preal_add_assoc RS sym]) 1);
qed "real_preal_minus_less_self";
Goalw [real_zero_def] "%~ %#m < 0r";
by (auto_tac (claset(),simpset() addsimps
[real_preal_def,real_less_def,real_minus]));
by (REPEAT(rtac exI 1));
by (EVERY[rtac conjI 1, rtac conjI 2]);
by (REPEAT(Blast_tac 2));
by (full_simp_tac (simpset() addsimps
[preal_self_less_add_right] @ preal_add_ac) 1);
qed "real_preal_minus_less_zero";
Goal "~ 0r < %~ %#m";
by (cut_facts_tac [real_preal_minus_less_zero] 1);
by (fast_tac (claset() addDs [real_less_trans]
addEs [real_less_irrefl]) 1);
qed "real_preal_not_minus_gt_zero";
Goalw [real_zero_def] " 0r < %#m";
by (auto_tac (claset(),simpset() addsimps
[real_preal_def,real_less_def,real_minus]));
by (REPEAT(rtac exI 1));
by (EVERY[rtac conjI 1, rtac conjI 2]);
by (REPEAT(Blast_tac 2));
by (full_simp_tac (simpset() addsimps
[preal_self_less_add_right] @ preal_add_ac) 1);
qed "real_preal_zero_less";
Goal "~ %#m < 0r";
by (cut_facts_tac [real_preal_zero_less] 1);
by (blast_tac (claset() addDs [real_less_trans]
addEs [real_less_irrefl]) 1);
qed "real_preal_not_less_zero";
Goal "0r < %~ %~ %#m";
by (simp_tac (simpset() addsimps
[real_preal_zero_less]) 1);
qed "real_minus_minus_zero_less";
(* another lemma *)
Goalw [real_zero_def] " 0r < %#m + %#m1";
by (auto_tac (claset(),simpset() addsimps
[real_preal_def,real_less_def,real_add]));
by (REPEAT(rtac exI 1));
by (EVERY[rtac conjI 1, rtac conjI 2]);
by (REPEAT(Blast_tac 2));
by (full_simp_tac (simpset() addsimps preal_add_ac) 1);
by (full_simp_tac (simpset() addsimps [preal_self_less_add_right,
preal_add_assoc RS sym]) 1);
qed "real_preal_sum_zero_less";
Goal "%~ %#m < %#m1";
by (auto_tac (claset(),simpset() addsimps
[real_preal_def,real_less_def,real_minus]));
by (REPEAT(rtac exI 1));
by (EVERY[rtac conjI 1, rtac conjI 2]);
by (REPEAT(Blast_tac 2));
by (full_simp_tac (simpset() addsimps preal_add_ac) 1);
by (full_simp_tac (simpset() addsimps [preal_self_less_add_right,
preal_add_assoc RS sym]) 1);
qed "real_preal_minus_less_all";
Goal "~ %#m < %~ %#m1";
by (cut_facts_tac [real_preal_minus_less_all] 1);
by (blast_tac (claset() addDs [real_less_trans]
addEs [real_less_irrefl]) 1);
qed "real_preal_not_minus_gt_all";
Goal "%~ %#m1 < %~ %#m2 ==> %#m2 < %#m1";
by (auto_tac (claset(),simpset() addsimps
[real_preal_def,real_less_def,real_minus]));
by (REPEAT(rtac exI 1));
by (EVERY[rtac conjI 1, rtac conjI 2]);
by (REPEAT(Blast_tac 2));
by (auto_tac (claset(),simpset() addsimps preal_add_ac));
by (asm_full_simp_tac (simpset() addsimps [preal_add_assoc RS sym]) 1);
by (auto_tac (claset(),simpset() addsimps preal_add_ac));
qed "real_preal_minus_less_rev1";
Goal "%#m1 < %#m2 ==> %~ %#m2 < %~ %#m1";
by (auto_tac (claset(),simpset() addsimps
[real_preal_def,real_less_def,real_minus]));
by (REPEAT(rtac exI 1));
by (EVERY[rtac conjI 1, rtac conjI 2]);
by (REPEAT(Blast_tac 2));
by (auto_tac (claset(),simpset() addsimps preal_add_ac));
by (asm_full_simp_tac (simpset() addsimps [preal_add_assoc RS sym]) 1);
by (auto_tac (claset(),simpset() addsimps preal_add_ac));
qed "real_preal_minus_less_rev2";
Goal "(%~ %#m1 < %~ %#m2) = (%#m2 < %#m1)";
by (blast_tac (claset() addSIs [real_preal_minus_less_rev1,
real_preal_minus_less_rev2]) 1);
qed "real_preal_minus_less_rev_iff";
Addsimps [real_preal_minus_less_rev_iff];
(*** linearity ***)
Goal "(R1::real) < R2 | R1 = R2 | R2 < R1";
by (res_inst_tac [("x","R1")] real_preal_trichotomyE 1);
by (ALLGOALS(res_inst_tac [("x","R2")] real_preal_trichotomyE));
by (auto_tac (claset() addSDs [preal_le_anti_sym],
simpset() addsimps [preal_less_le_iff,real_preal_minus_less_zero,
real_preal_zero_less,real_preal_minus_less_all]));
qed "real_linear";
Goal "!!(R1::real). [| R1 < R2 ==> P; R1 = R2 ==> P; \
\ R2 < R1 ==> P |] ==> P";
by (cut_inst_tac [("R1.0","R1"),("R2.0","R2")] real_linear 1);
by Auto_tac;
qed "real_linear_less2";
(*** Properties of <= ***)
Goalw [real_le_def] "~(w < z) ==> z <= (w::real)";
by (assume_tac 1);
qed "real_leI";
Goalw [real_le_def] "z<=w ==> ~(w<(z::real))";
by (assume_tac 1);
qed "real_leD";
val real_leE = make_elim real_leD;
Goal "(~(w < z)) = (z <= (w::real))";
by (blast_tac (claset() addSIs [real_leI,real_leD]) 1);
qed "real_less_le_iff";
Goalw [real_le_def] "~ z <= w ==> w<(z::real)";
by (Blast_tac 1);
qed "not_real_leE";
Goalw [real_le_def] "z < w ==> z <= (w::real)";
by (blast_tac (claset() addEs [real_less_asym]) 1);
qed "real_less_imp_le";
Goalw [real_le_def] "!!(x::real). x <= y ==> x < y | x = y";
by (cut_facts_tac [real_linear] 1);
by (blast_tac (claset() addEs [real_less_irrefl,real_less_asym]) 1);
qed "real_le_imp_less_or_eq";
Goalw [real_le_def] "z<w | z=w ==> z <=(w::real)";
by (cut_facts_tac [real_linear] 1);
by (fast_tac (claset() addEs [real_less_irrefl,real_less_asym]) 1);
qed "real_less_or_eq_imp_le";
Goal "(x <= (y::real)) = (x < y | x=y)";
by (REPEAT(ares_tac [iffI, real_less_or_eq_imp_le, real_le_imp_less_or_eq] 1));
qed "real_le_eq_less_or_eq";
Goal "w <= (w::real)";
by (simp_tac (simpset() addsimps [real_le_eq_less_or_eq]) 1);
qed "real_le_refl";
val prems = goal Real.thy "!!i. [| i <= j; j < k |] ==> i < (k::real)";
by (dtac real_le_imp_less_or_eq 1);
by (blast_tac (claset() addIs [real_less_trans]) 1);
qed "real_le_less_trans";
Goal "!! (i::real). [| i < j; j <= k |] ==> i < k";
by (dtac real_le_imp_less_or_eq 1);
by (blast_tac (claset() addIs [real_less_trans]) 1);
qed "real_less_le_trans";
Goal "[| i <= j; j <= k |] ==> i <= (k::real)";
by (EVERY1 [dtac real_le_imp_less_or_eq, dtac real_le_imp_less_or_eq,
rtac real_less_or_eq_imp_le, blast_tac (claset() addIs [real_less_trans])]);
qed "real_le_trans";
Goal "[| z <= w; w <= z |] ==> z = (w::real)";
by (EVERY1 [dtac real_le_imp_less_or_eq, dtac real_le_imp_less_or_eq,
fast_tac (claset() addEs [real_less_irrefl,real_less_asym])]);
qed "real_le_anti_sym";
Goal "[| ~ y < x; y ~= x |] ==> x < (y::real)";
by (rtac not_real_leE 1);
by (blast_tac (claset() addDs [real_le_imp_less_or_eq]) 1);
qed "not_less_not_eq_real_less";
Goal "(0r < %~R) = (R < 0r)";
by (res_inst_tac [("x","R")] real_preal_trichotomyE 1);
by (auto_tac (claset(),simpset() addsimps [real_preal_not_minus_gt_zero,
real_preal_not_less_zero,real_preal_zero_less,
real_preal_minus_less_zero]));
qed "real_minus_zero_less_iff";
Addsimps [real_minus_zero_less_iff];
Goal "(%~R < 0r) = (0r < R)";
by (res_inst_tac [("x","R")] real_preal_trichotomyE 1);
by (auto_tac (claset(),simpset() addsimps [real_preal_not_minus_gt_zero,
real_preal_not_less_zero,real_preal_zero_less,
real_preal_minus_less_zero]));
qed "real_minus_zero_less_iff2";
(** lemma **)
Goal "(0r < x) = (? y. x = %#y)";
by (auto_tac (claset(),simpset() addsimps [real_preal_zero_less]));
by (cut_inst_tac [("x","x")] real_preal_trichotomy 1);
by (blast_tac (claset() addSEs [real_less_irrefl,
real_preal_not_minus_gt_zero RS notE]) 1);
qed "real_gt_zero_preal_Ex";
Goal "%#z < x ==> ? y. x = %#y";
by (blast_tac (claset() addSDs [real_preal_zero_less RS real_less_trans]
addIs [real_gt_zero_preal_Ex RS iffD1]) 1);
qed "real_gt_preal_preal_Ex";
Goal "%#z <= x ==> ? y. x = %#y";
by (blast_tac (claset() addDs [real_le_imp_less_or_eq,
real_gt_preal_preal_Ex]) 1);
qed "real_ge_preal_preal_Ex";
Goal "y <= 0r ==> !x. y < %#x";
by (auto_tac (claset() addEs [real_le_imp_less_or_eq RS disjE]
addIs [real_preal_zero_less RSN(2,real_less_trans)],
simpset() addsimps [real_preal_zero_less]));
qed "real_less_all_preal";
Goal "~ 0r < y ==> !x. y < %#x";
by (blast_tac (claset() addSIs [real_less_all_preal,real_leI]) 1);
qed "real_less_all_real2";
(**** Derive alternative definition for real_less ****)
(** lemma **)
Goal "!!(R::real). ? A. S + A = R";
by (res_inst_tac [("x","%~S + R")] exI 1);
by (simp_tac (simpset() addsimps [real_add_minus,
real_add_zero_right] @ real_add_ac) 1);
qed "real_lemma_add_left_ex";
Goal "!!(R::real). R < S ==> ? T. R + T = S";
by (res_inst_tac [("x","R")] real_preal_trichotomyE 1);
by (ALLGOALS(res_inst_tac [("x","S")] real_preal_trichotomyE));
by (auto_tac (claset() addSDs [preal_le_anti_sym] addSDs [preal_less_add_left_Ex],
simpset() addsimps [preal_less_le_iff,real_preal_add,real_minus_add_eq,
real_preal_minus_less_zero,real_less_not_refl,real_minus_ex,real_add_assoc,
real_preal_zero_less,real_preal_minus_less_all,real_add_minus_left,
real_preal_not_less_zero,real_add_zero_left,real_lemma_add_left_ex]));
qed "real_less_add_left_Ex";
Goal "!!(R::real). R < S ==> ? T. 0r < T & R + T = S";
by (res_inst_tac [("x","R")] real_preal_trichotomyE 1);
by (ALLGOALS(res_inst_tac [("x","S")] real_preal_trichotomyE));
by (auto_tac (claset() addSDs [preal_less_add_left_Ex],
simpset() addsimps [real_preal_not_minus_gt_all,
real_preal_add, real_preal_not_less_zero,real_less_not_refl,
real_preal_not_minus_gt_zero,real_add_zero_left,real_minus_add_eq]));
by (res_inst_tac [("x","%#D")] exI 1);
by (res_inst_tac [("x","%#m+%#ma")] exI 2);
by (res_inst_tac [("x","%#m")] exI 3);
by (res_inst_tac [("x","%#D")] exI 4);
by (auto_tac (claset(),simpset() addsimps [real_preal_zero_less,
real_preal_sum_zero_less,real_add_minus_left,real_add_assoc,
real_add_minus,real_add_zero_right]));
by (simp_tac (simpset() addsimps [real_add_assoc RS sym,
real_add_minus_left,real_add_zero_left]) 1);
qed "real_less_add_positive_left_Ex";
(* lemmas *)
(** change naff name(s)! **)
Goal "(W < S) ==> (0r < S + %~W)";
by (dtac real_less_add_positive_left_Ex 1);
by (auto_tac (claset(),simpset() addsimps [real_add_minus,
real_add_zero_right] @ real_add_ac));
qed "real_less_sum_gt_zero";
Goal "!!S. T = S + W ==> S = T + %~W";
by (asm_simp_tac (simpset() addsimps [real_add_minus, real_add_zero_right]
@ real_add_ac) 1);
qed "real_lemma_change_eq_subj";
(* FIXME: long! *)
Goal "(0r < S + %~W) ==> (W < S)";
by (rtac ccontr 1);
by (dtac (real_leI RS real_le_imp_less_or_eq) 1);
by (auto_tac (claset(),
simpset() addsimps [real_less_not_refl,real_add_minus]));
by (EVERY1[dtac real_less_add_positive_left_Ex, etac exE, etac conjE]);
by (asm_full_simp_tac (simpset() addsimps [real_add_zero_left]) 1);
by (dtac real_lemma_change_eq_subj 1);
by (auto_tac (claset(),simpset() addsimps [real_minus_minus]));
by (dtac real_less_sum_gt_zero 1);
by (asm_full_simp_tac (simpset() addsimps [real_minus_add_eq] @ real_add_ac) 1);
by (EVERY1[rotate_tac 1, dtac (real_add_left_commute RS ssubst)]);
by (auto_tac (claset() addEs [real_less_asym],
simpset() addsimps [real_add_minus,real_add_zero_right]));
qed "real_sum_gt_zero_less";
Goal "(0r < S + %~W) = (W < S)";
by (blast_tac (claset() addIs [real_less_sum_gt_zero,
real_sum_gt_zero_less]) 1);
qed "real_less_sum_gt_0_iff";
Goal "((x::real) < y) = (%~y < %~x)";
by (rtac (real_less_sum_gt_0_iff RS subst) 1);
by (res_inst_tac [("W1","x")] (real_less_sum_gt_0_iff RS subst) 1);
by (simp_tac (simpset() addsimps [real_add_commute]) 1);
qed "real_less_swap_iff";
Goal "[| R + L = S; 0r < L |] ==> R < S";
by (rtac (real_less_sum_gt_0_iff RS iffD1) 1);
by (auto_tac (claset(),simpset() addsimps [
real_add_minus,real_add_zero_right] @ real_add_ac));
qed "real_lemma_add_positive_imp_less";
Goal "!!(R::real). ? T. 0r < T & R + T = S ==> R < S";
by (blast_tac (claset() addIs [real_lemma_add_positive_imp_less]) 1);
qed "real_ex_add_positive_left_less";
(*** alternative definition for real_less ***)
Goal "!!(R::real). (? T. 0r < T & R + T = S) = (R < S)";
by (blast_tac (claset() addSIs [real_less_add_positive_left_Ex,
real_ex_add_positive_left_less]) 1);
qed "real_less_iffdef";
Goal "(0r < x) = (%~x < x)";
by Safe_tac;
by (rtac ccontr 2 THEN forward_tac
[real_leI RS real_le_imp_less_or_eq] 2);
by (Step_tac 2);
by (dtac (real_minus_zero_less_iff RS iffD2) 2);
by (blast_tac (claset() addIs [real_less_trans]) 2);
by (auto_tac (claset(),simpset() addsimps
[real_gt_zero_preal_Ex,real_preal_minus_less_self]));
qed "real_gt_zero_iff";
Goal "(x < 0r) = (x < %~x)";
by (rtac (real_minus_zero_less_iff RS subst) 1);
by (stac real_gt_zero_iff 1);
by (Full_simp_tac 1);
qed "real_lt_zero_iff";
Goalw [real_le_def] "(0r <= x) = (%~x <= x)";
by (auto_tac (claset(),simpset() addsimps [real_lt_zero_iff RS sym]));
qed "real_ge_zero_iff";
Goalw [real_le_def] "(x <= 0r) = (x <= %~x)";
by (auto_tac (claset(),simpset() addsimps [real_gt_zero_iff RS sym]));
qed "real_le_zero_iff";
Goal "(%#m1 <= %#m2) = (m1 <= m2)";
by (auto_tac (claset() addSIs [preal_leI],
simpset() addsimps [real_less_le_iff RS sym]));
by (dtac preal_le_less_trans 1 THEN assume_tac 1);
by (etac preal_less_irrefl 1);
qed "real_preal_le_iff";
Goal "!!(x::real). [| 0r < x; 0r < y |] ==> 0r < x * y";
by (auto_tac (claset(),simpset() addsimps [real_gt_zero_preal_Ex]));
by (res_inst_tac [("x","y*ya")] exI 1);
by (full_simp_tac (simpset() addsimps [real_preal_mult]) 1);
qed "real_mult_order";
Goal "!!(x::real). [| x < 0r; y < 0r |] ==> 0r < x * y";
by (REPEAT(dtac (real_minus_zero_less_iff RS iffD2) 1));
by (dtac real_mult_order 1 THEN assume_tac 1);
by (Asm_full_simp_tac 1);
qed "real_mult_less_zero1";
Goal "!!(x::real). [| 0r <= x; 0r <= y |] ==> 0r <= x * y";
by (REPEAT(dtac real_le_imp_less_or_eq 1));
by (auto_tac (claset() addIs [real_mult_order,
real_less_imp_le],simpset() addsimps [real_le_refl]));
qed "real_le_mult_order";
Goal "!!(x::real). [| x <= 0r; y <= 0r |] ==> 0r <= x * y";
by (rtac real_less_or_eq_imp_le 1);
by (dtac real_le_imp_less_or_eq 1 THEN etac disjE 1);
by Auto_tac;
by (dtac real_le_imp_less_or_eq 1);
by (auto_tac (claset() addDs [real_mult_less_zero1],simpset()));
qed "real_mult_le_zero1";
Goal "!!(x::real). [| 0r <= x; y < 0r |] ==> x * y <= 0r";
by (rtac real_less_or_eq_imp_le 1);
by (dtac real_le_imp_less_or_eq 1 THEN etac disjE 1);
by Auto_tac;
by (dtac (real_minus_zero_less_iff RS iffD2) 1);
by (rtac (real_minus_zero_less_iff RS subst) 1);
by (blast_tac (claset() addDs [real_mult_order]
addIs [real_minus_mult_eq2 RS ssubst]) 1);
qed "real_mult_le_zero";
Goal "!!(x::real). [| 0r < x; y < 0r |] ==> x*y < 0r";
by (dtac (real_minus_zero_less_iff RS iffD2) 1);
by (dtac real_mult_order 1 THEN assume_tac 1);
by (rtac (real_minus_zero_less_iff RS iffD1) 1);
by (asm_full_simp_tac (simpset() addsimps [real_minus_mult_eq2]) 1);
qed "real_mult_less_zero";
Goalw [real_one_def] "0r < 1r";
by (auto_tac (claset() addIs [real_gt_zero_preal_Ex RS iffD2],
simpset() addsimps [real_preal_def]));
qed "real_zero_less_one";
(*** Completeness of reals ***)
(** use supremum property of preal and theorems about real_preal **)
(*** a few lemmas ***)
Goal "! x:P. 0r < x ==> ((? x:P. y < x) = (? X. %#X : P & y < %#X))";
by (blast_tac (claset() addSDs [bspec,real_gt_zero_preal_Ex RS iffD1]) 1);
qed "real_sup_lemma1";
Goal "[| ! x:P. 0r < x; ? x. x: P; ? y. !x: P. x < y |] \
\ ==> (? X. X: {w. %#w : P}) & (? Y. !X: {w. %#w : P}. X < Y)";
by (rtac conjI 1);
by (blast_tac (claset() addDs [bspec,real_gt_zero_preal_Ex RS iffD1]) 1);
by Auto_tac;
by (dtac bspec 1 THEN assume_tac 1);
by (forward_tac [bspec] 1 THEN assume_tac 1);
by (dtac real_less_trans 1 THEN assume_tac 1);
by (dtac (real_gt_zero_preal_Ex RS iffD1) 1 THEN etac exE 1);
by (res_inst_tac [("x","ya")] exI 1);
by Auto_tac;
by (dres_inst_tac [("x","%#X")] bspec 1 THEN assume_tac 1);
by (etac real_preal_lessD 1);
qed "real_sup_lemma2";
(*-------------------------------------------------------------
Completeness of Positive Reals
-------------------------------------------------------------*)
(* Supremum property for the set of positive reals *)
(* FIXME: long proof - can be improved - need only have one case split *)
(* will do for now *)
Goal "[| ! x:P. 0r < x; ? x. x: P; ? y. !x: P. x < y |] \
\ ==> (? S. !y. (? x: P. y < x) = (y < S))";
by (res_inst_tac [("x","%#psup({w. %#w : P})")] exI 1);
by Auto_tac;
by (forward_tac [real_sup_lemma2] 1 THEN Auto_tac);
by (case_tac "0r < ya" 1);
by (dtac (real_gt_zero_preal_Ex RS iffD1) 1);
by (dtac real_less_all_real2 2);
by Auto_tac;
by (rtac (preal_complete RS spec RS iffD1) 1);
by Auto_tac;
by (forward_tac [real_gt_preal_preal_Ex] 1);
by Auto_tac;
(* second part *)
by (rtac (real_sup_lemma1 RS iffD2) 1 THEN assume_tac 1);
by (case_tac "0r < ya" 1);
by (auto_tac (claset() addSDs [real_less_all_real2,
real_gt_zero_preal_Ex RS iffD1],simpset()));
by (forward_tac [real_sup_lemma2] 2 THEN Auto_tac);
by (forward_tac [real_sup_lemma2] 1 THEN Auto_tac);
by (rtac (preal_complete RS spec RS iffD2 RS bexE) 1);
by (Blast_tac 3);
by (Blast_tac 1);
by (Blast_tac 1);
by (Blast_tac 1);
qed "posreal_complete";
(*------------------------------------------------------------------
------------------------------------------------------------------*)
Goal "!!(A::real). A < B ==> A + C < B + C";
by (dtac (real_less_iffdef RS iffD2) 1);
by (rtac (real_less_iffdef RS iffD1) 1);
by (REPEAT(Step_tac 1));
by (full_simp_tac (simpset() addsimps real_add_ac) 1);
qed "real_add_less_mono1";
Goal "!!(A::real). A < B ==> C + A < C + B";
by (auto_tac (claset() addIs [real_add_less_mono1],
simpset() addsimps [real_add_commute]));
qed "real_add_less_mono2";
Goal "!!(A::real). A + C < B + C ==> A < B";
by (dres_inst_tac [("C","%~C")] real_add_less_mono1 1);
by (asm_full_simp_tac (simpset() addsimps [real_add_assoc,
real_add_minus,real_add_zero_right]) 1);
qed "real_less_add_right_cancel";
Goal "!!(A::real). C + A < C + B ==> A < B";
by (dres_inst_tac [("C","%~C")] real_add_less_mono2 1);
by (asm_full_simp_tac (simpset() addsimps [real_add_assoc RS sym,
real_add_minus_left,real_add_zero_left]) 1);
qed "real_less_add_left_cancel";
Goal "[| 0r < x; 0r < y |] ==> 0r < x + y";
by (REPEAT(dtac (real_gt_zero_preal_Ex RS iffD1) 1));
by (rtac (real_gt_zero_preal_Ex RS iffD2) 1);
by (Step_tac 1);
by (res_inst_tac [("x","y + ya")] exI 1);
by (full_simp_tac (simpset() addsimps [real_preal_add]) 1);
qed "real_add_order";
Goal "!!(x::real). [| 0r <= x; 0r <= y |] ==> 0r <= x + y";
by (REPEAT(dtac real_le_imp_less_or_eq 1));
by (auto_tac (claset() addIs [real_add_order,
real_less_imp_le],simpset() addsimps [real_add_zero_left,
real_add_zero_right,real_le_refl]));
qed "real_le_add_order";
Goal
"[| R1 < S1; R2 < S2 |] ==> R1 + R2 < S1 + (S2::real)";
by (dtac (real_less_iffdef RS iffD2) 1);
by (dtac (real_less_iffdef RS iffD2) 1);
by (rtac (real_less_iffdef RS iffD1) 1);
by Auto_tac;
by (res_inst_tac [("x","T + Ta")] exI 1);
by (auto_tac (claset(),simpset() addsimps [real_add_order] @ real_add_ac));
qed "real_add_less_mono";
Goal "!!(x::real). [| 0r <= x; 0r <= y |] ==> 0r <= x + y";
by (REPEAT(dtac real_le_imp_less_or_eq 1));
by (auto_tac (claset() addIs [real_add_order,
real_less_imp_le],simpset() addsimps [real_add_zero_left,
real_add_zero_right,real_le_refl]));
qed "real_le_add_order";
Goal "!!(q1::real). q1 <= q2 ==> x + q1 <= x + q2";
by (dtac real_le_imp_less_or_eq 1);
by (Step_tac 1);
by (auto_tac (claset() addSIs [real_le_refl,
real_less_imp_le,real_add_less_mono1],
simpset() addsimps [real_add_commute]));
qed "real_add_left_le_mono1";
Goal "!!(q1::real). q1 <= q2 ==> q1 + x <= q2 + x";
by (auto_tac (claset() addDs [real_add_left_le_mono1],
simpset() addsimps [real_add_commute]));
qed "real_add_le_mono1";
Goal "!!k l::real. [|i<=j; k<=l |] ==> i + k <= j + l";
by (etac (real_add_le_mono1 RS real_le_trans) 1);
by (simp_tac (simpset() addsimps [real_add_commute]) 1);
(*j moves to the end because it is free while k, l are bound*)
by (etac real_add_le_mono1 1);
qed "real_add_le_mono";
Goal "EX (x::real). x < y";
by (rtac (real_add_zero_right RS subst) 1);
by (res_inst_tac [("x","y + %~1r")] exI 1);
by (auto_tac (claset() addSIs [real_add_less_mono2],
simpset() addsimps [real_minus_zero_less_iff2,
real_zero_less_one]));
qed "real_less_Ex";
(*---------------------------------------------------------------------------------
An embedding of the naturals in the reals
---------------------------------------------------------------------------------*)
Goalw [real_nat_def] "%%#0 = 1r";
by (full_simp_tac (simpset() addsimps [pnat_one_iff RS sym,real_preal_def]) 1);
by (fold_tac [real_one_def]);
by (rtac refl 1);
qed "real_nat_one";
Goalw [real_nat_def] "%%#1 = 1r + 1r";
by (full_simp_tac (simpset() addsimps [real_preal_def,real_one_def,
pnat_two_eq,real_add,prat_pnat_add RS sym,preal_prat_add RS sym
] @ pnat_add_ac) 1);
qed "real_nat_two";
Goalw [real_nat_def]
"%%#n1 + %%#n2 = %%#(n1 + n2) + 1r";
by (full_simp_tac (simpset() addsimps [real_nat_one RS sym,
real_nat_def,real_preal_add RS sym,preal_prat_add RS sym,
prat_pnat_add RS sym,pnat_nat_add]) 1);
qed "real_nat_add";
Goal "%%#(n + 1) = %%#n + 1r";
by (res_inst_tac [("x1","1r")] (real_add_right_cancel RS iffD1) 1);
by (rtac (real_nat_add RS subst) 1);
by (full_simp_tac (simpset() addsimps [real_nat_two,real_add_assoc]) 1);
qed "real_nat_add_one";
Goal "Suc n = n + 1";
by Auto_tac;
qed "lemma";
Goal "%%#Suc n = %%#n + 1r";
by (stac lemma 1);
by (rtac real_nat_add_one 1);
qed "real_nat_Suc";
Goal "inj(real_nat)";
by (rtac injI 1);
by (rewtac real_nat_def);
by (dtac (inj_real_preal RS injD) 1);
by (dtac (inj_preal_prat RS injD) 1);
by (dtac (inj_prat_pnat RS injD) 1);
by (etac (inj_pnat_nat RS injD) 1);
qed "inj_real_nat";
Goalw [real_nat_def] "0r < %%#n";
by (rtac (real_gt_zero_preal_Ex RS iffD2) 1);
by (Blast_tac 1);
qed "real_nat_less_zero";
Goal "1r <= %%#n";
by (simp_tac (simpset() addsimps [real_nat_one RS sym]) 1);
by (induct_tac "n" 1);
by (auto_tac (claset(),simpset ()
addsimps [real_nat_Suc,real_le_refl,real_nat_one]));
by (res_inst_tac [("t","1r")] (real_add_zero_left RS subst) 1);
by (rtac real_add_le_mono 1);
by (auto_tac (claset(),simpset ()
addsimps [real_le_refl,real_nat_less_zero,
real_less_imp_le,real_add_zero_left]));
qed "real_nat_less_one";
Goal "rinv(%%#n) ~= 0r";
by (rtac ((real_nat_less_zero RS
real_not_refl2 RS not_sym) RS rinv_not_zero) 1);
qed "real_nat_rinv_not_zero";
Goal "rinv(%%#x) = rinv(%%#y) ==> x = y";
by (rtac (inj_real_nat RS injD) 1);
by (res_inst_tac [("n2","x")]
(real_nat_rinv_not_zero RS real_mult_left_cancel RS iffD1) 1);
by (full_simp_tac (simpset() addsimps [(real_nat_less_zero RS
real_not_refl2 RS not_sym) RS real_mult_inv_left]) 1);
by (asm_full_simp_tac (simpset() addsimps [(real_nat_less_zero RS
real_not_refl2 RS not_sym)]) 1);
qed "real_nat_rinv_inj";
Goal "0r < x ==> 0r < rinv x";
by (EVERY1[rtac ccontr, dtac real_leI]);
by (forward_tac [real_minus_zero_less_iff2 RS iffD2] 1);
by (forward_tac [real_not_refl2 RS not_sym] 1);
by (dtac (real_not_refl2 RS not_sym RS rinv_not_zero) 1);
by (EVERY1[dtac real_le_imp_less_or_eq, Step_tac]);
by (dtac real_mult_less_zero1 1 THEN assume_tac 1);
by (auto_tac (claset() addIs [real_zero_less_one RS real_less_asym],
simpset() addsimps [real_minus_mult_eq1 RS sym]));
qed "real_rinv_gt_zero";
Goal "x < 0r ==> rinv x < 0r";
by (forward_tac [real_not_refl2] 1);
by (dtac (real_minus_zero_less_iff RS iffD2) 1);
by (rtac (real_minus_zero_less_iff RS iffD1) 1);
by (dtac (real_minus_rinv RS sym) 1);
by (auto_tac (claset() addIs [real_rinv_gt_zero],
simpset()));
qed "real_rinv_less_zero";
Goal "x+x=x*(1r+1r)";
by (simp_tac (simpset() addsimps [real_add_mult_distrib2]) 1);
qed "real_add_self";
Goal "x < x + 1r";
by (rtac (real_less_sum_gt_0_iff RS iffD1) 1);
by (full_simp_tac (simpset() addsimps [real_zero_less_one,
real_add_assoc,real_add_minus,real_add_zero_right,
real_add_left_commute]) 1);
qed "real_self_less_add_one";
Goal "1r < 1r + 1r";
by (rtac real_self_less_add_one 1);
qed "real_one_less_two";
Goal "0r < 1r + 1r";
by (rtac ([real_zero_less_one,
real_one_less_two] MRS real_less_trans) 1);
qed "real_zero_less_two";
Goal "1r + 1r ~= 0r";
by (rtac (real_zero_less_two RS real_not_refl2 RS not_sym) 1);
qed "real_two_not_zero";
Addsimps [real_two_not_zero];
Goal "x*rinv(1r + 1r) + x*rinv(1r + 1r) = x";
by (stac real_add_self 1);
by (full_simp_tac (simpset() addsimps [real_mult_assoc]) 1);
qed "real_sum_of_halves";
Goal "!!(x::real). [| 0r<z; x<y |] ==> x*z<y*z";
by (rotate_tac 1 1);
by (dtac real_less_sum_gt_zero 1);
by (rtac real_sum_gt_zero_less 1);
by (dtac real_mult_order 1 THEN assume_tac 1);
by (asm_full_simp_tac (simpset() addsimps [real_add_mult_distrib2,
real_minus_mult_eq2 RS sym, real_mult_commute ]) 1);
qed "real_mult_less_mono1";
Goal "!!(y::real). [| 0r<z; x<y |] ==> z*x<z*y";
by (asm_simp_tac (simpset() addsimps [real_mult_commute,real_mult_less_mono1]) 1);
qed "real_mult_less_mono2";
Goal "!!(x::real). [| 0r<z; x*z<y*z |] ==> x<y";
by (forw_inst_tac [("x","x*z")] (real_rinv_gt_zero
RS real_mult_less_mono1) 1);
by (auto_tac (claset(),simpset() addsimps
[real_mult_assoc,real_not_refl2 RS not_sym]));
qed "real_mult_less_cancel1";
Goal "!!(x::real). [| 0r<z; z*x<z*y |] ==> x<y";
by (etac real_mult_less_cancel1 1);
by (asm_full_simp_tac (simpset() addsimps [real_mult_commute]) 1);
qed "real_mult_less_cancel2";
Goal "0r < z ==> (x*z < y*z) = (x < y)";
by (blast_tac (claset() addIs [real_mult_less_mono1,
real_mult_less_cancel1]) 1);
qed "real_mult_less_iff1";
Goal "0r < z ==> (z*x < z*y) = (x < y)";
by (blast_tac (claset() addIs [real_mult_less_mono2,
real_mult_less_cancel2]) 1);
qed "real_mult_less_iff2";
Addsimps [real_mult_less_iff1,real_mult_less_iff2];
Goal "!!(x::real). [| 0r<=z; x<y |] ==> x*z<=y*z";
by (EVERY1 [rtac real_less_or_eq_imp_le, dtac real_le_imp_less_or_eq]);
by (auto_tac (claset() addIs [real_mult_less_mono1],simpset()));
qed "real_mult_le_less_mono1";
Goal "!!(x::real). [| 0r<=z; x<y |] ==> z*x<=z*y";
by (asm_simp_tac (simpset() addsimps [real_mult_commute,real_mult_le_less_mono1]) 1);
qed "real_mult_le_less_mono2";
Goal "!!x y (z::real). [| 0r<=z; x<=y |] ==> z*x<=z*y";
by (dres_inst_tac [("x","x")] real_le_imp_less_or_eq 1);
by (auto_tac (claset() addIs [real_mult_le_less_mono2,real_le_refl],simpset()));
qed "real_mult_le_le_mono1";
Goal "!!(x::real). x < y ==> x < (x + y)*rinv(1r + 1r)";
by (dres_inst_tac [("C","x")] real_add_less_mono2 1);
by (dtac (real_add_self RS subst) 1);
by (dtac (real_zero_less_two RS real_rinv_gt_zero RS
real_mult_less_mono1) 1);
by (asm_full_simp_tac (simpset() addsimps [real_mult_assoc]) 1);
qed "real_less_half_sum";
Goal "!!(x::real). x < y ==> (x + y)*rinv(1r + 1r) < y";
by (dres_inst_tac [("C","y")] real_add_less_mono1 1);
by (dtac (real_add_self RS subst) 1);
by (dtac (real_zero_less_two RS real_rinv_gt_zero RS
real_mult_less_mono1) 1);
by (asm_full_simp_tac (simpset() addsimps [real_mult_assoc]) 1);
qed "real_gt_half_sum";
Goal "!!(x::real). x < y ==> EX r. x < r & r < y";
by (blast_tac (claset() addSIs [real_less_half_sum,real_gt_half_sum]) 1);
qed "real_dense";
Goal "(EX n. rinv(%%#n) < r) = (EX n. 1r < r * %%#n)";
by (Step_tac 1);
by (dres_inst_tac [("n1","n")] (real_nat_less_zero
RS real_mult_less_mono1) 1);
by (dres_inst_tac [("n2","n")] (real_nat_less_zero RS
real_rinv_gt_zero RS real_mult_less_mono1) 2);
by (auto_tac (claset(),simpset() addsimps [(real_nat_less_zero RS
real_not_refl2 RS not_sym),real_mult_assoc]));
qed "real_nat_rinv_Ex_iff";
Goalw [real_nat_def] "(%%#n < %%#m) = (n < m)";
by Auto_tac;
qed "real_nat_less_iff";
Addsimps [real_nat_less_iff];
Goal "0r < u ==> (u < rinv (%%#n)) = (%%#n < rinv(u))";
by (Step_tac 1);
by (res_inst_tac [("n2","n")] (real_nat_less_zero RS
real_rinv_gt_zero RS real_mult_less_cancel1) 1);
by (res_inst_tac [("x1","u")] ( real_rinv_gt_zero
RS real_mult_less_cancel1) 2);
by (auto_tac (claset(),simpset() addsimps [real_nat_less_zero,
real_not_refl2 RS not_sym]));
by (res_inst_tac [("z","u")] real_mult_less_cancel2 1);
by (res_inst_tac [("n1","n")] (real_nat_less_zero RS
real_mult_less_cancel2) 3);
by (auto_tac (claset(),simpset() addsimps [real_nat_less_zero,
real_not_refl2 RS not_sym,real_mult_assoc RS sym]));
qed "real_nat_less_rinv_iff";
Goal "0r < u ==> (u = rinv(%%#n)) = (%%#n = rinv u)";
by (auto_tac (claset(),simpset() addsimps [real_rinv_rinv,
real_nat_less_zero,real_not_refl2 RS not_sym]));
qed "real_nat_rinv_eq_iff";
(*
(*------------------------------------------------------------------
lemmas about upper bounds and least upper bound
------------------------------------------------------------------*)
Goalw [real_ub_def] "[| real_ub u S; x : S |] ==> x <= u";
by Auto_tac;
qed "real_ubD";
*)