Untitled Document

(114) Let us consider sets $A$ , $B$ , $C$ , $D$ . Suppose i. $A$ misses $D$ , and ii. $B$ misses $D$ , and iii. $C$ misses $D$ . Then $(A\mathop{{{\cup}}}B)\mathop{{\cup}}C$ misses $D$ . (115) $A\mathrel{{\not\subset}}{\emptyset}$ . (116) $X\mathop{{\cap}}(Y\mathop{{\cap}}Z)\mathrel{{=}}(X\mathop{{\cap}}Y)\mathop{{% \cap}}(X\mathop{{\cap}}Z)$ . (117) Let us consider sets $P$ , $G$ , $C$ . Suppose $C\mathrel{{\subseteq}}G$ . Then $P\mathop{{\setminus}}C\mathrel{{=}}(P\mathop{{\setminus}}G)\mathop{{\cup}}P% \mathop{{\cap}}(G\mathop{{\setminus}}C)$ .