Metamath Proof Explorer


Theorem naryrcl

Description: Reverse closure for n-ary (endo)functions. (Contributed by AV, 14-May-2024)

Ref Expression
Hypothesis naryfval.i
|- I = ( 0 ..^ N )
Assertion naryrcl
|- ( F e. ( N -aryF X ) -> ( N e. NN0 /\ X e. _V ) )

Proof

Step Hyp Ref Expression
1 naryfval.i
 |-  I = ( 0 ..^ N )
2 df-naryf
 |-  -aryF = ( x e. NN0 , n e. _V |-> ( n ^m ( n ^m ( 0 ..^ x ) ) ) )
3 2 elmpocl
 |-  ( F e. ( N -aryF X ) -> ( N e. NN0 /\ X e. _V ) )