Matching. Drag sentences from the right to the correct
location in the proof box.
universe of discourse = the counting numbers: 1,2,3, etc.
Gxy: x is greater than y
Now, show that the sentence
'(%w)(^z)Gzw' is true.
substitution instance of (1)
must also be true (where 'n' is picked to name the appropriate
'(^z)Gzn' is true, all it's substitution
instances must be true.
'(^z)Gzn's substitution instance
this last result that 'Gnn' is is true is an absurdity for
no number is greater than itself!
Hence, the initial assumption
is wrong and (*) is false.