Expression#

class Expression(*args, **kwargs)[source]#

Bases: Object

Abstract base class for expressions.

An Expression can be either a Type or a Term.

Parameters:

args – Arguments
kwargs – Annotations.

Returns:

Unfolded args#

`Expression.unfolded_args`	Expression arguments unfolded.
`Expression.get_unfolded_args`()	Gets the expression arguments unfolded.

Type constructors#

`Expression.type_constructors`	Set of type constructors occurring in expression.
`Expression.get_type_constructors`()	Gets the set of type constructors occurring in expression.
`Expression.has_type_constructors`()	Tests whether some type constructor occurs in expression.

Type variables#

`Expression.type_variables`	Set of type variables occurring in expression.
`Expression.get_type_variables`()	Gets the set of type variables occurring in expression.
`Expression.has_type_variables`()	Tests whether some type variable occurs in expression.

Instantiation#

Expression.instantiate(theta)

Applies type-variable instantiation theta to expression.