Metamath Proof Explorer


Theorem ssbr

Description: Implication from a subclass relationship of binary relations. (Contributed by Peter Mazsa, 11-Nov-2019)

Ref Expression
Assertion ssbr ( 𝐴𝐵 → ( 𝐶 𝐴 𝐷𝐶 𝐵 𝐷 ) )

Proof

Step Hyp Ref Expression
1 id ( 𝐴𝐵𝐴𝐵 )
2 1 ssbrd ( 𝐴𝐵 → ( 𝐶 𝐴 𝐷𝐶 𝐵 𝐷 ) )