In

Retiming synchronous circuitry , why put a negative sign to

*d(u)* in step 1 ? Why there is no subtraction operation for

*W(u, v)* in step 3 ?

Note:

1. The quantity W(u, v) is the minimum number of registers on any path from vertex u to vertex v

2. The quantity D(u, v) is the maximum total propagation delay on any critical path from u to v