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 } ) |