Metamath Proof Explorer


Theorem pstr

Description: A poset is transitive. (Contributed by NM, 12-May-2008) (Revised by Mario Carneiro, 30-Apr-2015)

Ref Expression
Assertion pstr R PosetRel A R B B R C A R C

Proof

Step Hyp Ref Expression
1 pslem R PosetRel A R B B R C A R C A R A R A A R B B R A A = B
2 1 simp1d R PosetRel A R B B R C A R C
3 2 3impib R PosetRel A R B B R C A R C