Metamath Proof Explorer


Theorem elpmapat

Description: Member of the projective map of an atom. (Contributed by NM, 27-Jan-2012)

Ref Expression
Hypotheses pmapat.a
|- A = ( Atoms ` K )
pmapat.m
|- M = ( pmap ` K )
Assertion elpmapat
|- ( ( K e. HL /\ P e. A ) -> ( X e. ( M ` P ) <-> X = P ) )

Proof

Step Hyp Ref Expression
1 pmapat.a
 |-  A = ( Atoms ` K )
2 pmapat.m
 |-  M = ( pmap ` K )
3 1 2 pmapat
 |-  ( ( K e. HL /\ P e. A ) -> ( M ` P ) = { P } )
4 3 eleq2d
 |-  ( ( K e. HL /\ P e. A ) -> ( X e. ( M ` P ) <-> X e. { P } ) )
5 elsn2g
 |-  ( P e. A -> ( X e. { P } <-> X = P ) )
6 5 adantl
 |-  ( ( K e. HL /\ P e. A ) -> ( X e. { P } <-> X = P ) )
7 4 6 bitrd
 |-  ( ( K e. HL /\ P e. A ) -> ( X e. ( M ` P ) <-> X = P ) )