Description: Theorem to move a conjunct in and out of a negation. (Contributed by NM, 9-Nov-2003)
Ref | Expression | ||
---|---|---|---|
Assertion | nan | ⊢ ( ( 𝜑 → ¬ ( 𝜓 ∧ 𝜒 ) ) ↔ ( ( 𝜑 ∧ 𝜓 ) → ¬ 𝜒 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | impexp | ⊢ ( ( ( 𝜑 ∧ 𝜓 ) → ¬ 𝜒 ) ↔ ( 𝜑 → ( 𝜓 → ¬ 𝜒 ) ) ) | |
2 | imnan | ⊢ ( ( 𝜓 → ¬ 𝜒 ) ↔ ¬ ( 𝜓 ∧ 𝜒 ) ) | |
3 | 2 | imbi2i | ⊢ ( ( 𝜑 → ( 𝜓 → ¬ 𝜒 ) ) ↔ ( 𝜑 → ¬ ( 𝜓 ∧ 𝜒 ) ) ) |
4 | 1 3 | bitr2i | ⊢ ( ( 𝜑 → ¬ ( 𝜓 ∧ 𝜒 ) ) ↔ ( ( 𝜑 ∧ 𝜓 ) → ¬ 𝜒 ) ) |