src/HOL/Hilbert_Choice.thy
changeset 47988 e4b69e10b990
parent 46950 d0181abdbdac
child 48891 c0eafbd55de3
     1.1 --- a/src/HOL/Hilbert_Choice.thy	Thu May 24 17:05:30 2012 +0200
     1.2 +++ b/src/HOL/Hilbert_Choice.thy	Thu May 24 17:25:53 2012 +0200
     1.3 @@ -443,7 +443,7 @@
     1.4    have "h ` A = B"
     1.5    proof safe
     1.6      fix a assume "a \<in> A"
     1.7 -    thus "h a \<in> B" using SUB1 2 3 by (case_tac "a \<in> A'", auto)
     1.8 +    thus "h a \<in> B" using SUB1 2 3 by (cases "a \<in> A'") auto
     1.9    next
    1.10      fix b assume *: "b \<in> B"
    1.11      show "b \<in> h ` A"