> QUANT_INSTANTIATE_CONV [] ``?x. ((x=7) \/ (7 = x)) /\ P x``;
val it = |- (?x. ((x=7) \/ (7 = x)) /\ P x) = P 7 : thm
> QUANT_INSTANTIATE_CONV [] ``?x. !y. (x=7) /\ P x y``;
val it = |- (?x. !y. (x=7) /\ P x y) = (!y. P 7 y) : thm
> QUANT_INSTANTIATE_CONV [] ``?x. (f(8 + 2) = f(x + 2)) /\ P(f (x + 2))``;
val it = |- (?x. (f(8 + 2) = f(x + 2)) /\ P(f (x + 2))) = P(f (8 + 2)) : thm
> QUANT_INSTANTIATE_CONV [std_qp] ``!x. IS_SOME x ==> P x``;
val it = |- (!x. IS_SOME x ==> P x) = (!x_x'. P (SOME x_x')) : thm
> QUANT_INSTANTIATE_CONV [std_qp] ``!l. (~(l = []) ==> (LENGTH l > 0))``;
val it |- (!l. (~(l = []) ==> (LENGTH l > 0))) <=>
(!l_t l_h. LENGTH (l_h::l_t) > 0) : thm