Description: Commutation of conjunction inside an existential quantifier. (Contributed by NM, 18-Aug-1993)
Ref | Expression | ||
---|---|---|---|
Assertion | exancom | ⊢ ( ∃ 𝑥 ( 𝜑 ∧ 𝜓 ) ↔ ∃ 𝑥 ( 𝜓 ∧ 𝜑 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ancom | ⊢ ( ( 𝜑 ∧ 𝜓 ) ↔ ( 𝜓 ∧ 𝜑 ) ) | |
2 | 1 | exbii | ⊢ ( ∃ 𝑥 ( 𝜑 ∧ 𝜓 ) ↔ ∃ 𝑥 ( 𝜓 ∧ 𝜑 ) ) |