Oh yeah Read the proof again It s okay for the product to be negative zero I am not saying this is incorrect I am making no assumptions I showed that 1 0 0 and then I showed that 1 0 0 and by transitivity of equality what this means is that the left hand side which is the same equals the rhs of 0 and 0 respectively therefore 0 and 0 must be the same these are equal No rocket science required here Melchoir