A symmetric split is accepted only from equal capacitor sources. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.
highlighted = computed this step
A split row first proves the two capacitances match
The midpoint is accepted only from two equal-capacitance sources across the same rail.
Ca=Cb=2FVs=8V
Equal split keeps the midpoint at one half of the rail
Each row rebuilds the split from two equal capacitors and a different source rail.
Vs8V10V12VVmid4V5V6Vsourcesequalequalequal
Equal source capacitors split the rail
The split row cites two equal capacitance sources before accepting the midpoint.