src/ZF/ex/misc.ML
changeset 3000 7ecb8b6a3d7f
parent 2496 40efb87985b5
child 4091 771b1f6422a8
equal deleted inserted replaced
2999:fad7cc426242 3000:7ecb8b6a3d7f
     6 Miscellaneous examples for Zermelo-Fraenkel Set Theory 
     6 Miscellaneous examples for Zermelo-Fraenkel Set Theory 
     7 Composition of homomorphisms, Pastre's examples, ...
     7 Composition of homomorphisms, Pastre's examples, ...
     8 *)
     8 *)
     9 
     9 
    10 writeln"ZF/ex/misc";
    10 writeln"ZF/ex/misc";
       
    11 
       
    12 (*Nice Blast_tac benchmark.  Proved in 0.3s; old tactics can't manage it!*)
       
    13 goal ZF.thy "!!S. ALL x:S. ALL y:S. x<=y ==> EX z. S <= {z}";
       
    14 by (Blast_tac 1);
       
    15 result();
    11 
    16 
    12 set_current_thy"Perm";
    17 set_current_thy"Perm";
    13 
    18 
    14 (*Example 12 (credited to Peter Andrews) from
    19 (*Example 12 (credited to Peter Andrews) from
    15  W. Bledsoe.  A Maximal Method for Set Variables in Automatic Theorem-proving.
    20  W. Bledsoe.  A Maximal Method for Set Variables in Automatic Theorem-proving.