Theorem fmtno0prm

Description: The 0 th Fermat number is a prime (_first Fermat prime_). (Contributed by AV, 13-Jun-2021)

	Ref	Expression
Assertion	fmtno0prm	$$⊢\mathrm{FermatNo}\left(0\right)\in \mathbb{P}$$

Proof

Step	Hyp	Ref	Expression
1		fmtno0	$$⊢\mathrm{FermatNo}\left(0\right)=3$$
2		3prm	$$⊢3\in \mathbb{P}$$
3	1 2	eqeltri	$$⊢\mathrm{FermatNo}\left(0\right)\in \mathbb{P}$$