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 Rel R
nprrel.2 ¬ A V
Assertion nprrel ¬ A R B

Proof

Step Hyp Ref Expression
1 nprrel12.1 Rel R
2 nprrel.2 ¬ A V
3 1 brrelex1i A R B A V
4 2 3 mto ¬ A R B