src/HOL/Hoare/Pointers0.thy
changeset 17778 93d7e524417a
parent 16417 9bc16273c2d4
child 35101 6ce9177d6b38
equal deleted inserted replaced
17777:05f5532a8289 17778:93d7e524417a
   294   INV {\<exists>ps. Path tl p ps X}
   294   INV {\<exists>ps. Path tl p ps X}
   295   DO p := p^.tl OD
   295   DO p := p^.tl OD
   296   {p = X}"
   296   {p = X}"
   297 apply vcg_simp
   297 apply vcg_simp
   298   apply blast
   298   apply blast
   299  apply clarsimp
       
   300  apply(erule disjE)
       
   301   apply clarsimp
       
   302  apply fastsimp
   299  apply fastsimp
   303 apply clarsimp
   300 apply clarsimp
   304 done
   301 done
   305 
   302 
   306 text{*Now it dawns on us that we do not need the list witness at all --- it
   303 text{*Now it dawns on us that we do not need the list witness at all --- it