This is a 'standard' sudoku puzzle; all values are numbers in the range 1 through 9.
abcdefghi
A Ha + Ba Bh + Ec Gc + Hg
B Gc × Hg
C Eb × Fh Fa × Hf Ab × Ba Ic − Gh
D
E Bf + Gd Hb − Ai Bh − Ca
F
G
H Cb − Bh Bc − Aa Aa − Gc
I Cd × Cf Eh + Hi