Description: Equality deduction for singletons. (Contributed by NM, 22-Jan-2004)
Ref | Expression | ||
---|---|---|---|
Hypothesis | sneqd.1 | ⊢ ( 𝜑 → 𝐴 = 𝐵 ) | |
Assertion | sneqd | ⊢ ( 𝜑 → { 𝐴 } = { 𝐵 } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sneqd.1 | ⊢ ( 𝜑 → 𝐴 = 𝐵 ) | |
2 | sneq | ⊢ ( 𝐴 = 𝐵 → { 𝐴 } = { 𝐵 } ) | |
3 | 1 2 | syl | ⊢ ( 𝜑 → { 𝐴 } = { 𝐵 } ) |