Metamath Proof Explorer


Theorem infeu

Description: An infimum is unique. (Contributed by AV, 6-Oct-2020)

Ref Expression
Hypotheses infmo.1 φROrA
infeu.2 φxAyB¬yRxyAxRyzBzRy
Assertion infeu φ∃!xAyB¬yRxyAxRyzBzRy

Proof

Step Hyp Ref Expression
1 infmo.1 φROrA
2 infeu.2 φxAyB¬yRxyAxRyzBzRy
3 1 infmo φ*xAyB¬yRxyAxRyzBzRy
4 reu5 ∃!xAyB¬yRxyAxRyzBzRyxAyB¬yRxyAxRyzBzRy*xAyB¬yRxyAxRyzBzRy
5 2 3 4 sylanbrc φ∃!xAyB¬yRxyAxRyzBzRy