Metamath Proof Explorer


Theorem ressco

Description: comp is unaffected by restriction. (Contributed by Mario Carneiro, 5-Jan-2017)

Ref Expression
Hypotheses resshom.1
|- D = ( C |`s A )
ressco.2
|- .x. = ( comp ` C )
Assertion ressco
|- ( A e. V -> .x. = ( comp ` D ) )

Proof

Step Hyp Ref Expression
1 resshom.1
 |-  D = ( C |`s A )
2 ressco.2
 |-  .x. = ( comp ` C )
3 df-cco
 |-  comp = Slot ; 1 5
4 1nn0
 |-  1 e. NN0
5 5nn
 |-  5 e. NN
6 4 5 decnncl
 |-  ; 1 5 e. NN
7 1nn
 |-  1 e. NN
8 5nn0
 |-  5 e. NN0
9 1lt10
 |-  1 < ; 1 0
10 7 8 4 9 declti
 |-  1 < ; 1 5
11 1 2 3 6 10 resslem
 |-  ( A e. V -> .x. = ( comp ` D ) )