dest_vartype : hol_type -> string
STRUCTURE
SYNOPSIS
Breaks a type variable down to its name.
FAILURE
Fails with dest_vartype if the type is not a type variable.
EXAMPLE
- dest_vartype alpha;
> val it = "'a" : string

- try dest_vartype bool;

Exception raised at Type.dest_vartype:
not a type variable

SEEALSO
HOL  Kananaskis-14