Theorem sq2

Description: The square of 2 is 4. (Contributed by NM, 22-Aug-1999)

	Ref	Expression
Assertion	sq2	$$⊢2^2=4$$

Proof

Step	Hyp	Ref	Expression
1		2cn	$$⊢2\in ℂ$$
2	1	sqvali	$$⊢2^2=2\cdot 2$$
3		2t2e4	$$⊢2\cdot 2=4$$
4	2 3	eqtri	$$⊢2^2=4$$