diff -r a0460a450cf9 -r bbfc360db011 doc-src/TutorialI/Overview/FP1.thy
--- a/doc-src/TutorialI/Overview/FP1.thy	Mon Jul 01 12:50:35 2002 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,302 +0,0 @@
-(*<*)theory FP1 = Main:(*>*)
-
-lemma "if xs = ys
-       then rev xs = rev ys
-       else rev xs \<noteq> rev ys"
-by auto
-
-lemma "case xs of
-         []   \<Rightarrow> tl xs = xs
-       | y#ys \<Rightarrow> tl xs \<noteq> xs"
-apply(case_tac xs)
-by auto
-
-
-subsection{*More Types*}
-
-
-subsubsection{*Natural Numbers*}
-
-consts sum :: "nat \<Rightarrow> nat"
-primrec "sum 0 = 0"
-        "sum (Suc n) = Suc n + sum n"
-
-lemma "sum n + sum n = n*(Suc n)"
-apply(induct_tac n)
-apply(auto)
-done
-
-text{*Some examples of linear arithmetic:*}
-
-lemma "\<lbrakk> \<not> m < n; m < n+(1::int) \<rbrakk> \<Longrightarrow> m = n"
-by(auto)
-
-lemma "min i (max j k) = max (min k i) (min i (j::nat))"
-by(arith)
-
-text{*Not proved automatically because it involves multiplication:*}
-
-lemma "n*n = n \<Longrightarrow> n=0 \<or> n=(1::int)"
-(*<*)oops(*>*)
-
-
-subsubsection{*Pairs*}
-
-lemma "fst(x,y) = snd(z,x)"
-by auto
-
-
-
-subsection{*Definitions*}
-
-consts xor :: "bool \<Rightarrow> bool \<Rightarrow> bool"
-defs xor_def: "xor x y \<equiv> x \<and> \<not>y \<or> \<not>x \<and> y"
-
-constdefs nand :: "bool \<Rightarrow> bool \<Rightarrow> bool"
-         "nand x y \<equiv> \<not>(x \<and> y)"
-
-lemma "\<not> xor x x"
-apply(unfold xor_def)
-by auto
-
-
-
-subsection{*Simplification*}
-
-
-subsubsection{*Simplification Rules*}
-
-lemma fst_conv[simp]: "fst(x,y) = x"
-by auto
-
-text{*Setting and resetting the @{text simp} attribute:*}
-
-declare fst_conv[simp]
-declare fst_conv[simp del]
-
-
-subsubsection{*The Simplification Method*}
-
-lemma "x*(y+1) = y*(x+1::nat)"
-apply simp
-(*<*)oops(*>*)
-
-
-subsubsection{*Adding and Deleting Simplification Rules*}
-
-lemma "\<forall>x::nat. x*(y+z) = r"
-apply (simp add: add_mult_distrib2)
-(*<*)oops(*>*)text_raw{* \isanewline\isanewline *}
-
-lemma "rev(rev(xs @ [])) = xs"
-apply (simp del: rev_rev_ident)
-(*<*)oops(*>*)
-
-subsubsection{*Assumptions*}
-
-lemma "\<lbrakk> xs @ zs = ys @ xs; [] @ xs = [] @ [] \<rbrakk> \<Longrightarrow> ys = zs"
-by simp
-
-lemma "\<forall>x. f x = g (f (g x)) \<Longrightarrow> f [] = f [] @ []"
-by(simp (no_asm))
-
-subsubsection{*Rewriting with Definitions*}
-
-lemma "xor A (\<not>A)"
-apply(simp only: xor_def)
-apply simp
-done
-
-
-subsubsection{*Conditional Equations*}
-
-lemma hd_Cons_tl[simp]: "xs \<noteq> []  \<Longrightarrow>  hd xs # tl xs = xs"
-by(case_tac xs, simp_all)
-
-lemma "xs \<noteq> [] \<Longrightarrow> hd(rev xs) # tl(rev xs) = rev xs"
-by simp
-
-
-subsubsection{*Automatic Case Splits*}
-
-lemma "\<forall>xs. if xs = [] then A else B"
-apply simp
-(*<*)oops(*>*)text_raw{* \isanewline\isanewline *}
-
-lemma "case xs @ [] of [] \<Rightarrow> P | y#ys \<Rightarrow> Q ys y"
-apply simp
-apply(simp split: list.split)
-(*<*)oops(*>*)
-
-
-subsubsection{*Arithmetic*}
-
-text{*Is simple enough for the default arithmetic:*}
-lemma "\<lbrakk> \<not> m < n; m < n+(1::nat) \<rbrakk> \<Longrightarrow> m = n"
-by simp
-
-text{*Contains boolean combinations and needs full arithmetic:*}
-lemma "\<not> m < n \<and> m < n+(1::nat) \<Longrightarrow> m = n"
-apply simp
-by(arith)
-
-(*<*)
-subsubsection{*Tracing*}
-
-lemma "rev [a] = []"
-apply(simp)
-oops
-(*>*)
-
-
-subsection{*Case Study: Compiling Expressions*}
-
-
-subsubsection{*Expressions*}
-
-types 'v binop = "'v \<Rightarrow> 'v \<Rightarrow> 'v"
-
-datatype ('a,'v)expr = Cex 'v
-                     | Vex 'a
-                     | Bex "'v binop"  "('a,'v)expr"  "('a,'v)expr"
-
-consts value :: "('a,'v)expr \<Rightarrow> ('a \<Rightarrow> 'v) \<Rightarrow> 'v"
-primrec
-"value (Cex v) env = v"
-"value (Vex a) env = env a"
-"value (Bex f e1 e2) env = f (value e1 env) (value e2 env)"
-
-
-subsubsection{*The Stack Machine*}
-
-datatype ('a,'v) instr = Const 'v
-                       | Load 'a
-                       | Apply "'v binop"
-
-consts exec :: "('a,'v)instr list \<Rightarrow> ('a\<Rightarrow>'v) \<Rightarrow> 'v list \<Rightarrow> 'v list"
-primrec
-"exec [] s vs = vs"
-"exec (i#is) s vs = (case i of
-    Const v  \<Rightarrow> exec is s (v#vs)
-  | Load a   \<Rightarrow> exec is s ((s a)#vs)
-  | Apply f  \<Rightarrow> exec is s ((f (hd vs) (hd(tl vs)))#(tl(tl vs))))"
-
-
-subsubsection{*The Compiler*}
-
-consts comp :: "('a,'v)expr \<Rightarrow> ('a,'v)instr list"
-primrec
-"comp (Cex v)       = [Const v]"
-"comp (Vex a)       = [Load a]"
-"comp (Bex f e1 e2) = (comp e2) @ (comp e1) @ [Apply f]"
-
-theorem "exec (comp e) s [] = [value e s]"
-(*<*)oops(*>*)
-
-
-
-subsection{*Advanced Datatypes*}
-
-
-subsubsection{*Mutual Recursion*}
-
-datatype 'a aexp = IF   "'a bexp" "'a aexp" "'a aexp"
-                 | Sum  "'a aexp" "'a aexp"
-                 | Var 'a
-                 | Num nat
-and      'a bexp = Less "'a aexp" "'a aexp"
-                 | And  "'a bexp" "'a bexp"
-                 | Neg  "'a bexp"
-
-
-consts  evala :: "'a aexp \<Rightarrow> ('a \<Rightarrow> nat) \<Rightarrow> nat"
-        evalb :: "'a bexp \<Rightarrow> ('a \<Rightarrow> nat) \<Rightarrow> bool"
-
-primrec
-  "evala (IF b a1 a2) env =
-     (if evalb b env then evala a1 env else evala a2 env)"
-  "evala (Sum a1 a2) env = evala a1 env + evala a2 env"
-  "evala (Var v) env = env v"
-  "evala (Num n) env = n"
-
-  "evalb (Less a1 a2) env = (evala a1 env < evala a2 env)"
-  "evalb (And b1 b2) env = (evalb b1 env \<and> evalb b2 env)"
-  "evalb (Neg b) env = (\<not> evalb b env)"
-
-consts substa :: "('a \<Rightarrow> 'b aexp) \<Rightarrow> 'a aexp \<Rightarrow> 'b aexp"
-       substb :: "('a \<Rightarrow> 'b aexp) \<Rightarrow> 'a bexp \<Rightarrow> 'b bexp"
-
-primrec
-  "substa s (IF b a1 a2) =
-     IF (substb s b) (substa s a1) (substa s a2)"
-  "substa s (Sum a1 a2) = Sum (substa s a1) (substa s a2)"
-  "substa s (Var v) = s v"
-  "substa s (Num n) = Num n"
-
-  "substb s (Less a1 a2) = Less (substa s a1) (substa s a2)"
-  "substb s (And b1 b2) = And (substb s b1) (substb s b2)"
-  "substb s (Neg b) = Neg (substb s b)"
-
-lemma substitution_lemma:
- "evala (substa s a) env = evala a (\<lambda>x. evala (s x) env) \<and>
-  evalb (substb s b) env = evalb b (\<lambda>x. evala (s x) env)"
-apply(induct_tac a and b)
-by simp_all
-
-
-subsubsection{*Nested Recursion*}
-
-datatype tree = C "tree list"
-
-text{*Some trees:*}
-term "C []"
-term "C [C [C []], C []]"
-
-consts
-mirror :: "tree \<Rightarrow> tree"
-mirrors:: "tree list \<Rightarrow> tree list"
-
-primrec
-  "mirror(C ts) = C(mirrors ts)"
-
-  "mirrors [] = []"
-  "mirrors (t # ts) = mirrors ts @ [mirror t]"
-
-lemma "mirror(mirror t) = t \<and> mirrors(mirrors ts) = ts"
-apply(induct_tac t and ts)
-apply simp_all
-(*<*)oops(*>*)
-
-text{*
-\begin{exercise}
-Complete the above proof.
-\end{exercise}
-*}
-
-subsubsection{*Datatypes Involving Functions*}
-
-datatype ('a,'i)bigtree = Tip | Br 'a "'i \<Rightarrow> ('a,'i)bigtree"
-
-text{*A big tree:*}
-term "Br 0 (\<lambda>i. Br i (\<lambda>n. Tip))"
-
-consts map_bt :: "('a \<Rightarrow> 'b) \<Rightarrow> ('a,'i)bigtree \<Rightarrow> ('b,'i)bigtree"
-primrec
-"map_bt f Tip      = Tip"
-"map_bt f (Br a F) = Br (f a) (\<lambda>i. map_bt f (F i))"
-
-lemma "map_bt (g o f) T = map_bt g (map_bt f T)"
-apply(induct_tac T, rename_tac[2] F)
-apply simp_all
-done
-
-text{* This is \emph{not} allowed:
-\begin{verbatim}
-datatype lambda = C "lambda => lambda"
-\end{verbatim}
-
-\begin{exercise}
-Define a datatype of ordinals and the ordinal $\Gamma_0$.
-\end{exercise}
-*}
-(*<*)end(*>*)