Fixed-point substitution is scanned across candidate values. 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 fixed point is found by substitution
The checked source row is the middle row: one half returns one half.
f(x)=2x+41
Neighbor candidates fail the same substitution
The table keeps the map fixed and changes only the candidate. The fixed bit turns on only when output and candidate match.