Since conjunction is a commutative and associative operation, the formal setting-up of sequent theory normally includes structural rules for rewriting the sequent Γ accordingly—for example for deducing B , A ⊢ C {\displaystyle {\mathcal {B}},{\mathcal {A}}\vdash {\mathcal {C}}} from A , B ⊢ C {\displaystyle {\mathcal {A}},{\mathcal {B}}\vdash {\mathcal {C}}} .
因为合取是交换性和结合性的操作，相继式理论的形式架设通常包括相应的结构规则来重写相继式的Γ - 例如 B , A ⊢ C {\displaystyle {\mathcal {B}},{\mathcal {A}}\vdash {\mathcal {C}}} 演绎自 A , B ⊢ C {\displaystyle {\mathcal {A}},{\mathcal {B}}\vdash {\mathcal {C}}} 。