Metamath Proof Explorer


Theorem uun2221

Description: A deduction unionizing a non-unionized collection of virtual hypotheses. (Contributed by Alan Sare, 30-Dec-2016) (Proof modification is discouraged.) (New usage is discouraged.) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypothesis uun2221.1 φ φ ψ φ χ
Assertion uun2221 ψ φ χ

Proof

Step Hyp Ref Expression
1 uun2221.1 φ φ ψ φ χ
2 3anass φ φ ψ φ φ φ ψ φ
3 anabs5 φ φ ψ φ φ ψ φ
4 2 3 bitri φ φ ψ φ φ ψ φ
5 ancom φ ψ ψ φ
6 5 anbi2i φ φ ψ φ ψ φ
7 4 6 bitr4i φ φ ψ φ φ φ ψ
8 anabs5 φ φ ψ φ ψ
9 8 5 bitri φ φ ψ ψ φ
10 7 9 bitri φ φ ψ φ ψ φ
11 10 imbi1i φ φ ψ φ χ ψ φ χ
12 1 11 mpbi ψ φ χ