The target below should equal 0, since 2x + c = a + b + c = 6c, and Mod[6c,3] == 0
But Mathematica seems to be unable to simplify this expression containing Mod?
It says "target-1/4\ Mod[c+2\ x,3] is not a well-formed equation."
Eliminate[{a == b + c, b == 2 c, a == x + y, b == x - y,
target - 1/4 Mod[2 x + c, 3]}, {x, a, b, y}]
GroebnerBasiswith aModulus: In[304]:= pols = {-a + b + c, -b + 2 c, -a + x + y, -b + x - y, 4target - (2 x + c) + 3k}; GroebnerBasis[pols, target, {a, b, c, x}, Modulus -> 3]Out[305]= {target}
– Daniel Lichtblau Jun 29 '21 at 18:28