mk_varTerm.mk_var : string * hol_type -> term
Constructs a variable of given name and type.
If v is a string and ty is a HOL type, then
mk_var(v, ty) returns a HOL variable.
Never fails.
mk_var can be used to construct variables with names
which are not acceptable to the term parser. In particular, a variable
with the name of a known constant can be constructed using
mk_var.
Term.dest_var, Term.is_var, Term.mk_const, Term.mk_comb, Term.mk_abs