Typo fix in predefined variables (#214)

src/y0/dsl.py

@@ -1563,7 +1563,7 @@ def _iter_variables(self) -> Iterable[Variable]:
 U1, U2, U3, U4, U5, U6 = [Variable(f"U{i}") for i in range(1, 7)]
 V1, V2, V3, V4, V5, V6 = [Variable(f"V{i}") for i in range(1, 7)]
 W0, W1, W2, W3, W4, W5, W6 = [Variable(f"W{i}") for i in range(7)]
-M1, M2, M2, M3, M4, M5, M6 = [Variable(f"M{i}") for i in range(7)]
+M0, M1, M2, M3, M4, M5, M6 = [Variable(f"M{i}") for i in range(7)]
 X1, X2, X3, X4, X5, X6 = [Variable(f"X{i}") for i in range(1, 7)]
 Y1, Y2, Y3, Y4, Y5, Y6 = [Variable(f"Y{i}") for i in range(1, 7)]
 Z1, Z2, Z3, Z4, Z5, Z6 = [Variable(f"Z{i}") for i in range(1, 7)]