Description: Existential elimination rule of natural deduction. (Contributed by ML, 17-Jul-2020)
Ref | Expression | ||
---|---|---|---|
Hypotheses | exlimimd.1 | ⊢ ( 𝜑 → ∃ 𝑥 𝜓 ) | |
exlimimd.2 | ⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) ) | ||
Assertion | exlimimd | ⊢ ( 𝜑 → 𝜒 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | exlimimd.1 | ⊢ ( 𝜑 → ∃ 𝑥 𝜓 ) | |
2 | exlimimd.2 | ⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) ) | |
3 | 2 | imp | ⊢ ( ( 𝜑 ∧ 𝜓 ) → 𝜒 ) |
4 | 1 3 | exlimddv | ⊢ ( 𝜑 → 𝜒 ) |