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 φφψφχ
Assertion uun2221 ψφχ

Proof

Step Hyp Ref Expression
1 uun2221.1 φφψφχ
2 3anass φφψφφφψφ
3 anabs5 φφψφφψφ
4 2 3 bitri φφψφφψφ
5 ancom φψψφ
6 5 anbi2i φφψφψφ
7 4 6 bitr4i φφψφφφψ
8 anabs5 φφψφψ
9 8 5 bitri φφψψφ
10 7 9 bitri φφψφψφ
11 10 imbi1i φφψφχψφχ
12 1 11 mpbi ψφχ