Theorem 1p1e2apr1 28731

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.)

Assertion

Ref	Expression
1p1e2apr1	⊢ (1 + 1) = 2

Proof of Theorem 1p1e2apr1

Step	Hyp	Ref	Expression
1		df-2 11966	. 2 ⊢ 2 = (1 + 1)
2	1	eqcomi 2747	1 ⊢ (1 + 1) = 2

Syntax hints:   = wceq 1539  (class class class)co 7255  1c1 10803   + caddc 10805  2c2 11958

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1799  ax-4 1813  ax-5 1914  ax-6 1972  ax-7 2012  ax-9 2118  ax-ext 2709

This theorem depends on definitions:  df-bi 206  df-an 396  df-ex 1784  df-cleq 2730  df-2 11966

This theorem is referenced by: (None)