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Metamath Proof Explorer


Theorem gen21

Description: Virtual deduction generalizing rule for one quantifying variables and two virtual hypothesis. gen21 is alrimdv with virtual deductions. (Contributed by Alan Sare, 25-Jul-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypothesis gen21.1 φ , ψ χ
Assertion gen21 φ , ψ x χ

Proof

Step Hyp Ref Expression
1 gen21.1 φ , ψ χ
2 1 dfvd2i φ ψ χ
3 2 alrimdv φ ψ x χ
4 3 dfvd2ir φ , ψ x χ