If ty is an application of a type operator Tyop, which
was declared in theory Thy, to a list of types Args, then
dest_thy_type ty returns {Tyop,Thy,Args}.
FAILURE
Fails if ty is a type variable.
EXAMPLE
- dest_thy_type (alpha --> bool);
> val it = {Args = [`:'a`, `:bool`], Thy = "min", Tyop = "fun"} :
- try dest_thy_type alpha;
Exception raised at Type.dest_thy_type: