Metamath Proof Explorer


Theorem nprrel

Description: No proper class is related to anything via any relation. (Contributed by Roy F. Longton, 30-Jul-2005)

Ref Expression
Hypotheses nprrel12.1 RelR
nprrel.2 ¬AV
Assertion nprrel ¬ARB

Proof

Step Hyp Ref Expression
1 nprrel12.1 RelR
2 nprrel.2 ¬AV
3 1 brrelex1i ARBAV
4 2 3 mto ¬ARB