coercion u
coercion uri
Declares u as an implicit coercion from the type of its last argument (source) to its codomain (target). Every time a term x of type source is used with expected type target, Matita automatically replaces x with (u ? … ? x) to avoid a typing error.
Implicit coercions are not displayed to the user: (u ? … ? x) is rendered simply as x.
When a coercion u is declared from source s to target t and there is already a coercion u' of target s or source t, a composite implicit coercion is automatically computed by Matita.