Description: A symmetry with E. .
See negsym1 for more information. (Contributed by Anthony Hart, 4-Sep-2011)
Ref | Expression | ||
---|---|---|---|
Assertion | exisym1 | ⊢ ( ∃ 𝑥 ∃ 𝑥 ⊥ → ∃ 𝑥 𝜑 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfe1 | ⊢ Ⅎ 𝑥 ∃ 𝑥 𝜑 | |
2 | falim | ⊢ ( ⊥ → 𝜑 ) | |
3 | 2 | eximi | ⊢ ( ∃ 𝑥 ⊥ → ∃ 𝑥 𝜑 ) |
4 | 1 3 | exlimi | ⊢ ( ∃ 𝑥 ∃ 𝑥 ⊥ → ∃ 𝑥 𝜑 ) |