Metamath Proof Explorer


Theorem funrel

Description: A function is a relation. (Contributed by NM, 1-Aug-1994)

Ref Expression
Assertion funrel
|- ( Fun A -> Rel A )

Proof

Step Hyp Ref Expression
1 df-fun
 |-  ( Fun A <-> ( Rel A /\ ( A o. `' A ) C_ _I ) )
2 1 simplbi
 |-  ( Fun A -> Rel A )