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| Mirrors > Home > MPE Home > Th. List > 1p1e2apr1 | Structured version Visualization version GIF version | ||
| Description: One plus one equals two. Using proof-shortening techniques pioneered by Mr. Mel L. O'Cat, along with the latest supercomputer technology, Prof. Loof Lirpa and colleagues were able to shorten Whitehead and Russell's 360-page proof that 1+1=2 in Principia Mathematica to this remarkable proof only two steps long, thus establishing a new world's record for this famous theorem. (Contributed by Prof. Loof Lirpa, 1-Apr-2008.) (Proof modification is discouraged.) (New usage is discouraged.) |
| Ref | Expression |
|---|---|
| 1p1e2apr1 | ⊢ (1 + 1) = 2 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-2 12309 | . 2 ⊢ 2 = (1 + 1) | |
| 2 | 1 | eqcomi 2771 | 1 ⊢ (1 + 1) = 2 |
| Colors of variables: wff setvar class |
| This proof depends on syntax axioms: = wceq 1569 (class class class)co 7412 1c1 11107 + caddc 11109 2c2 12301 |
| This proof depends on axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1824 ax-4 1838 ax-5 1939 ax-6 1996 ax-7 2037 ax-9 2152 ax-ext 2734 |
| This proof depends on definitions: df-bi 210 df-an 401 df-ex 1809 df-cleq 2754 df-2 12309 |
| This theorem is used by: (None) |
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