Hey Thomas
Thanks for your quick response.
I realised that the sign of ∂ conv_out  / ∂ bias  SHOULD change according to the equation conv_out = input *correl* weight + bias
but what I want to know is- if i make a new function Conv2d_modified with the mentioned changes and then when I call backward() on the loss function ,then will the REQUIRED sign change of ∂ conv_out  / ∂ bias will take place?