Description: Extend wff definition to include "all some" applied to a class, which means ps is true whenever ph is true for x in A , and there is at least one x in A where ph is true. (Contributed by David A. Wheeler, 20-Oct-2018) (Revised by David A. Wheeler, 12-Jul-2026)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | wrals | wff ∀∃ 𝑥 ∈ 𝐴 ( 𝜑 → 𝜓 ) |