Logtalk reference manual
Predicate directive: protocol/1-2
Contents > Reference Manual > Directives > protocol/1-2

## protocol/1-2

#### Description

    protocol(Protocol)

    protocol(Protocol,
        extends(Protocols))

Starting protocol directive.

#### Template and modes

    protocol(+protocol_identifier)

    protocol(+protocol_identifier,
        extends(+extended_protocols))

#### Examples

    :- protocol(listp).

    :- protocol(listp,
        extends(compoundp)).

    :- protocol(queuep,
        extends(protected::listp)).