PSPEC_TAC : term * term -> tactic
        A ?- t
   =================  PSPEC_TAC (q,p)
    A ?- !x. t[p/q]
- g `1 + 2 = 2 + 1`;
> val it =
    Proof manager status: 1 proof.
    1. Incomplete:
         Initial goal:
         1 + 2 = 2 + 1
- e (PSPEC_TAC (Term`(1,2)`, Term`(x:num,y:num)`));
OK..
1 subgoal:
> val it =
    !(x,y). x + y = y + x
    
     : proof