Metamath Proof Explorer


Theorem rals1d

Description: Deduction rule: Given "all some" applied to a class, you can extract the "for all" part. (Contributed by David A. Wheeler, 20-Oct-2018) (Revised by David A. Wheeler, 12-Jul-2026)

Ref Expression
Hypothesis rals1d.1 φ ∀∃ x A ψ χ
Assertion rals1d φ x A ψ χ

Proof

Step Hyp Ref Expression
1 rals1d.1 φ ∀∃ x A ψ χ
2 df-rals ∀∃ x A ψ χ x A ψ χ x A ψ
3 1 2 sylib φ x A ψ χ x A ψ
4 3 simpld φ x A ψ χ