is this true about existential variables ?

[asti...@gmail.com]

Is it true , that an existential variable must always have a Type ;
by contrast a universal variable is not limited to the domain of things which have a Type ?

Is there a third class of vaiable : the variable which can provision a material value ? By this I mean that the variable MIGHT be abstract , in which case it has no associated material value , but because "abstract about a material value" , must provision a material value when not abstract ?

_universal = _ ,
_existential = functor_name_as_type(_optional_value) ,
_material_example_1 #=< sup , _material_example_1 #>= inf ,
_material_example_2 = functor_name_as_enum .
_material_example_3 = atom_as_intern_string .

~~kintalken~~