Part of My code is as follow

Temp1 = log(1 + a / (b + c)) * 1.4427 - log(1 + a / (d(n,1) + c)) * 1.4427;

where a and c are constant, d is a variable and b is affine

When I run my code, this error appeared:

Disciplined convex programming error:

Cannot perform the operation: {positive constant} ./ {real affine}

I try to add inv_pos() to my code to deal with this error, then modify my code as

Temp1 = log(1 + a * inv_pos(b + c)) * 1.4427 - log(1 + a * inv_pos(d(n,1) + c)) * 1.4427;

Then the other error appeared:

Disciplined convex programming error:

Illegal operation: log( {convex} ).

These errors bothered me for a long time and make me feel headache. Could you please tell me how should I deal with them?