src/ZF/equalities.thy
changeset 13357 6f54e992777e
parent 13356 c9cfe1638bf2
child 13544 895994073bdf
equal deleted inserted replaced
13356:c9cfe1638bf2 13357:6f54e992777e
    16 lemma [simp]: "((P-->Q) <-> (P-->R)) <-> (P --> (Q<->R))"
    16 lemma [simp]: "((P-->Q) <-> (P-->R)) <-> (P --> (Q<->R))"
    17 by blast
    17 by blast
    18 
    18 
    19 (*FIXME: move to ZF.thy or even to FOL.thy??*)
    19 (*FIXME: move to ZF.thy or even to FOL.thy??*)
    20 lemma not_disj_iff_imp: "~P | Q <-> (P-->Q)"
    20 lemma not_disj_iff_imp: "~P | Q <-> (P-->Q)"
    21 by blast
       
    22 
       
    23 (*FIXME: move to upair once it's Isar format*)
       
    24 lemma the_eq_trivial [simp]: "(THE x. x = a) = a"
       
    25 by blast
    21 by blast
    26 
    22 
    27 (** Monotonicity of implications -- some could go to FOL **)
    23 (** Monotonicity of implications -- some could go to FOL **)
    28 
    24 
    29 lemma in_mono: "A<=B ==> x:A --> x:B"
    25 lemma in_mono: "A<=B ==> x:A --> x:B"