xt+1 = sin(A yt) - cos(B xt)

yt+1 = sin(C xt) - cos(D yt)

case 1

parameters: A = -2.24, B = 0.43, C = -0.65, D = -2.43
Lyapunov exponents (log with base-e):  0.3590, -0.8637
Lyapunov dimension: 1.4156

case 2

parameters: A = 2.01, B = -2.53, C = 1.61, D = -0.33
Lyapunov exponents (log with base-e):  0.4340, -0.3432
Lyapunov dimension: 2.0

case 3

parameters: A = -2.0, B = -2.0, C = -1.2, D = 2.0
Lyapunov exponents (log with base-e):  0.5001, -0.2283
Lyapunov dimension: 2.0

Reference

Probing the strange attractions of chaos

Alexander Keewatin Dewdney

Scientific American, 257, 108–111 (1987)

https://www.jstor.org/stable/24979428