Metamath Proof Explorer


Theorem noxpordfr

Description: Next we establish the foundedness of the relationship. (Contributed by Scott Fenton, 19-Aug-2024)

Ref Expression
Hypotheses noxpord.1
|- R = { <. a , b >. | a e. ( ( _L ` b ) u. ( _R ` b ) ) }
noxpord.2
|- S = { <. x , y >. | ( x e. ( No X. No ) /\ y e. ( No X. No ) /\ ( ( ( 1st ` x ) R ( 1st ` y ) \/ ( 1st ` x ) = ( 1st ` y ) ) /\ ( ( 2nd ` x ) R ( 2nd ` y ) \/ ( 2nd ` x ) = ( 2nd ` y ) ) /\ x =/= y ) ) }
Assertion noxpordfr
|- S Fr ( No X. No )

Proof

Step Hyp Ref Expression
1 noxpord.1
 |-  R = { <. a , b >. | a e. ( ( _L ` b ) u. ( _R ` b ) ) }
2 noxpord.2
 |-  S = { <. x , y >. | ( x e. ( No X. No ) /\ y e. ( No X. No ) /\ ( ( ( 1st ` x ) R ( 1st ` y ) \/ ( 1st ` x ) = ( 1st ` y ) ) /\ ( ( 2nd ` x ) R ( 2nd ` y ) \/ ( 2nd ` x ) = ( 2nd ` y ) ) /\ x =/= y ) ) }
3 1 lrrecfr
 |-  R Fr No
4 3 a1i
 |-  ( T. -> R Fr No )
5 2 4 4 frxp2
 |-  ( T. -> S Fr ( No X. No ) )
6 5 mptru
 |-  S Fr ( No X. No )