Address Word Structure
The EDVAC employed a 44 bit word with a 4 bit op code and 4 10 bit address fields.

While the use of the fields varied a lot, the ADD instruction was typical. The memory location in field 1 was added to the memory location in field 2 and the result placed into the memory location in field 3. Execution of code then continued at the location addressed by field 4.

Thus we can summarize C = A + B; GOTO D

As for simulation with pseudo codes, we can deduce that for the Accumulator + One address machines popular at the time, the C = A + B would be simulated with three instructions and the GOTO part would be omitted. Thus three-plus-zero. It might look something like (stylized not actual code):

; ADD A,B,C
LD Acc, A
ADD Acc, B
ST Acc, C


For more on EDVAC please see:

https://babel.hathitrust.org/cgi/pt?id=mdp.39015002095639;view=1up;seq=87