Description: Introduction of conjunct inside of a contradiction. Would be used in elfvov1 . (Contributed by SN, 18-May-2025)
Ref | Expression | ||
---|---|---|---|
Assertion | intnanrt | ⊢ ( ¬ 𝜑 → ¬ ( 𝜑 ∧ 𝜓 ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpl | ⊢ ( ( 𝜑 ∧ 𝜓 ) → 𝜑 ) | |
2 | 1 | con3i | ⊢ ( ¬ 𝜑 → ¬ ( 𝜑 ∧ 𝜓 ) ) |