Rule 1:

Prerequisite 1: If $SPO>SP{O}^{\ast }$ then $C_y$ is $C_O$;

Prerequisite 2: If $SPO<SP{O}^{\ast }$ then $C_y$ is $\overline{C_O}$;

Input: $SPO=SPO\prime$

Conclusion: $C_y$ is $C_O$ or $\overline{C_O}$;

(If $C_y$ is $C_O$, then end of the inference.)

Rule 2:

Prerequisite 1: If $SPI>SP{I}^{\ast }$ then $C_y$ is $C_I$;

Prerequisite 2: If $SPI<SP{I}^{\ast }$ then $C_y$ is $C_R$;

Input: $SPI=SPI$′

Conclusion: $C_y$ is $C_I$ or $\overline{C_R}$;