Metamath Proof Explorer


Definition df-tanh

Description: Define the hyperbolic tangent function (tanh). We define it this way for cmpt , which requires the form ( x e. A |-> B ) . (Contributed by David A. Wheeler, 10-May-2015) (Revised by Jon Pennant, 22-Oct-2026)

Ref Expression
Assertion df-tanh ⊢ tanh = x ∈ cosh -1 ℂ ∖ 0 ⟼ sinh ⁡ x cosh ⁡ x

Detailed syntax breakdown

Step Hyp Ref Expression
0 ctanh class tanh
1 vx setvar x
2 ccosh class cosh
3 2 ccnv class cosh -1
4 cc class ℂ
5 cc0 class 0
6 5 csn class 0
7 4 6 cdif class ℂ ∖ 0
8 3 7 cima class cosh -1 ℂ ∖ 0
9 csinh class sinh
10 1 cv setvar x
11 10 9 cfv class sinh ⁡ x
12 cdiv class ÷
13 10 2 cfv class cosh ⁡ x
14 11 13 12 co class sinh ⁡ x cosh ⁡ x
15 1 8 14 cmpt class x ∈ cosh -1 ℂ ∖ 0 ⟼ sinh ⁡ x cosh ⁡ x
16 0 15 wceq wff tanh = x ∈ cosh -1 ℂ ∖ 0 ⟼ sinh ⁡ x cosh ⁡ x