Equation

Defines the flows in left-hand side either by an expression or by cases.

Syntax

lhs = expr  or
definition_by_cases

where each equation can define one (or several) flows according to the expression and the form of lhs:

lhs: ID (, ID)* (,..)?  or ()
Eventually, ID can be replaced by "_" meaning that the corresponding flow is not named.

The keyword ,.. is equivalent to a list of "_": flows are not named.

Type

'T = 'T

The left-hand side and the expression are of the same type and size.

When there is an _ in left-hand side, there is no typing constraint on the corresponding flow.

This type signature extends to groups.