Equations sum of energy and momentum colliding masses m 1 and m 2 , (velocities v 1 , v 2 , u 1 , u 2 correspond to the velocity parameters s 1 , s 2 , s 3 , s 4 ), after dividing by adequate power c are as follows: m 1 cosh ⁡ ⁡ ( s 1 ) + m 2 cosh ⁡ ⁡ ( s 2 ) = m 1 cosh ⁡ ⁡ ( s 3 ) + m 2 cosh ⁡ ⁡ ( s 4 ) m 1 sinh ⁡ ⁡ ( s 1 ) + m 2 sinh ⁡ ⁡ ( s 2 ) = m 1 sinh ⁡ ⁡ ( s 3 ) + m 2 sinh ⁡ ⁡ ( s 4 )