Metamath Proof Explorer


Theorem ntrneif1o

Description: If (pseudo-)interior and (pseudo-)neighborhood functions are related by the operator, F , we may characterize the relation as part of a 1-to-1 onto function. (Contributed by RP, 29-May-2021)

Ref Expression
Hypotheses ntrnei.o
|- O = ( i e. _V , j e. _V |-> ( k e. ( ~P j ^m i ) |-> ( l e. j |-> { m e. i | l e. ( k ` m ) } ) ) )
ntrnei.f
|- F = ( ~P B O B )
ntrnei.r
|- ( ph -> I F N )
Assertion ntrneif1o
|- ( ph -> F : ( ~P B ^m ~P B ) -1-1-onto-> ( ~P ~P B ^m B ) )

Proof

Step Hyp Ref Expression
1 ntrnei.o
 |-  O = ( i e. _V , j e. _V |-> ( k e. ( ~P j ^m i ) |-> ( l e. j |-> { m e. i | l e. ( k ` m ) } ) ) )
2 ntrnei.f
 |-  F = ( ~P B O B )
3 ntrnei.r
 |-  ( ph -> I F N )
4 1 2 3 ntrneibex
 |-  ( ph -> B e. _V )
5 4 pwexd
 |-  ( ph -> ~P B e. _V )
6 1 5 4 2 fsovf1od
 |-  ( ph -> F : ( ~P B ^m ~P B ) -1-1-onto-> ( ~P ~P B ^m B ) )