((a + b)*d + c)*E --------------------- 1 + ((a + b)*d + c)*E
2.71828182845905*(c + d*(a + b))/(1.0 + 2.71828182845905*c + 2.71828182845905*d*(a + b))
E*(c + a*d + b*d) ----------------------- 1 + E*c + E*a*d + E*b*d
E*(c + a*d + b*d) ----------------------- 1 + E*c + E*a*d + E*b*d
1 1 - ----------------------- 1 + E*c + E*a*d + E*b*d