X_SKOLEM_CONVConv.X_SKOLEM_CONV : (term -> conv)Introduces a user-supplied Skolem function.
X_SKOLEM_CONV takes two arguments. The first is a
variable f, which must range over functions of the
appropriate type, and the second is a term of the form
!x1...xn. ?y. P. Given these arguments,
X_SKOLEM_CONV returns the theorem:
|- (!x1...xn. ?y. P) = (?f. !x1...xn. tm[f x1 ... xn/y])which expresses the fact that a skolem function f of the
universally quantified variables x1...xn may be introduced
in place of the the existentially quantified value y.
X_SKOLEM_CONV f tm fails if f is not a
variable, or if the input term tm is not a term of the form
!x1...xn. ?y. P, or if the variable f is free
in tm, or if the type of f does not match its
intended use as an n-place curried function from the
variables x1...xn to a value having the same type as
y.