Metamath Proof Explorer


Theorem sylan2i

Description: A syllogism inference. (Contributed by NM, 1-Aug-1994)

Ref Expression
Hypotheses sylan2i.1 φθ
sylan2i.2 ψχθτ
Assertion sylan2i ψχφτ

Proof

Step Hyp Ref Expression
1 sylan2i.1 φθ
2 sylan2i.2 ψχθτ
3 1 a1i ψφθ
4 3 2 sylan2d ψχφτ