Metamath Proof Explorer


Theorem nabi2i

Description: Constructor rule for -/\ . (Contributed by Anthony Hart, 2-Sep-2011)

Ref Expression
Hypotheses nabi2i.1 φ ψ
nabi2i.2 χ ψ
Assertion nabi2i χ φ

Proof

Step Hyp Ref Expression
1 nabi2i.1 φ ψ
2 nabi2i.2 χ ψ
3 1 bicomi ψ φ
4 3 nanbi2i χ ψ χ φ
5 2 4 mpbi χ φ