逆运算

$R^{- 1} = {< y, x >∣< x, y >\in R}$

复合运算

$R \circ S = {< x, z >∣< x, y >\in R \land < y, z >\in S}$

$R ↾ A = {< x, y >∣ x R y \land x \in A}$

$R [A] = ran (R ↾ A)$

$F \circ (G \cup H) = F \circ G \cup F \circ H$ $F \circ (G \cap H) \subseteq F \circ G \cap F \circ H$