Metamath Proof Explorer


Theorem fzf

Description: Establish the domain and codomain of the finite integer sequence function. (Contributed by Scott Fenton, 8-Aug-2013) (Revised by Mario Carneiro, 16-Nov-2013)

Ref Expression
Assertion fzf
|- ... : ( ZZ X. ZZ ) --> ~P ZZ

Proof

Step Hyp Ref Expression
1 zex
 |-  ZZ e. _V
2 ssrab2
 |-  { k e. ZZ | ( m <_ k /\ k <_ n ) } C_ ZZ
3 1 2 elpwi2
 |-  { k e. ZZ | ( m <_ k /\ k <_ n ) } e. ~P ZZ
4 3 rgen2w
 |-  A. m e. ZZ A. n e. ZZ { k e. ZZ | ( m <_ k /\ k <_ n ) } e. ~P ZZ
5 df-fz
 |-  ... = ( m e. ZZ , n e. ZZ |-> { k e. ZZ | ( m <_ k /\ k <_ n ) } )
6 5 fmpo
 |-  ( A. m e. ZZ A. n e. ZZ { k e. ZZ | ( m <_ k /\ k <_ n ) } e. ~P ZZ <-> ... : ( ZZ X. ZZ ) --> ~P ZZ )
7 4 6 mpbi
 |-  ... : ( ZZ X. ZZ ) --> ~P ZZ