集合の全体、空集合

word(,c) … \(\text{Set}\)  
def …【\(\text{Set}\)】≃【\(\{ {\sf x} \mid \top \} \)
\(\text{Set0}\)\(x \in \text{Set}\)◀ O
\(\text{Set1}\)\(X \subset \text{Set}\)◀ O

word(,s) … \(\emptyset\)  
\(\emptyset.\)\(\emptyset = \{ x \mid {\perp} \} \)
\(\emptyset0\)\(x \notin \emptyset\)/\(\emptyset.\)◀ O
\(\emptyset1\)\(\emptyset \subset X\)/\(\subset.\)/\(\emptyset.\)◀ O
\(\emptyset{.}{.}\)\(x = \emptyset \Longleftrightarrow \not\exists y \, ( y \in x )\)◀ \(=.\)\(\emptyset0\)

合併、共通部分、差

word(cc,c) … \(\cup\)  \(\cap\)  \(\mathop\setminus\)  
def …【\({\sf C} \cup {\sf D}\)】≃【\(\{ {\sf x} \mid {\sf x} \in {\sf C} \mathbin{\rm o\!r} {\sf x} \in {\sf D} \} \)
def …【\({\sf C} \cap {\sf D}\)】≃【\(\{ {\sf x} \mid {\sf x} \in {\sf C} , {\sf x} \in {\sf D} \} \)
def …【\({\sf C} \mathop\setminus {\sf D}\)】≃【\(\{ {\sf x} \mid {\sf x} \in {\sf C} , {\sf x} \notin {\sf D} \} \)

word(ss,s) … \(\cup\)  \(\cap\)  \(\mathop\setminus\)  
\(\cup.\)\(X \cup Y = X \cup Y\)
\(\cap.\)\(X \cap Y = X \cap Y\)
\(\setminus.\)\(X \mathop\setminus Y = X \mathop\setminus Y\)
\({\subset}\text{u}\)\(X \subset Y \Longleftrightarrow X \cup Y = Y\)/\(\subset.\)/\(=.\)/\(\cup.\)◀ O
\({\subset}\text{a}\)\(X \subset Y \Longleftrightarrow X \cap Y = X\)/\(\subset.\)/\(=.\)/\(\cap.\)◀ O

総合併、総共通部分

word(c,c) … \(\bigcup\)  \(\bigcap\)  
def …【\(\bigcup {\sf C}\)】≃【\(\{ {\sf x} \mid \exists {\sf y} \in {\sf C} . {\sf x} \in {\sf y} \} \)
def …【\(\bigcap {\sf C}\)】≃【\(\{ {\sf x} \mid \forall {\sf y} \in {\sf C} . {\sf x} \in {\sf y} \} \)

word(s,s) … \(\bigcup\)  \(\bigcap\)  
\(\bigcup.\)\(\bigcup X = \bigcup X\)
\(\bigcap.\)\(X \neq \emptyset \Longrightarrow \bigcap X = \bigcap X\)
\(\bigcap\emptyset\)\(\bigcap \emptyset = \text{Set}\)/\(\emptyset.\)◀ O

\(\cup_1\)\(X = \bigcup \{ X \}\)/\(=.\)/\(\bigcup.\)/\(\text{set}_1.\)◀ O
\(\cap_1\)\(X = \bigcap \{ X \}\)/\(=.\)/\(\bigcap.\)/\(\text{set}_1.\)◀ O
\(\cup_2\)\(X \cup Y = \bigcup \{ X , Y \}\)/\(=.\)/\(\cup.\)/\(\bigcup.\)/\(\text{set}_2.\)◀ O
\(\cap_2\)\(X \cap Y = \bigcap \{ X , Y \}\)/\(=.\)/\(\cap.\)/\(\bigcap.\)/\(\text{set}_2.\)◀ O
集合は1点集合により分割されます。
\(\text{sep_set}\)\(X = \bigcup _{ x \in X } \{ x \}\)/\(=.\)◀ \(\text{set}_1.\)

べき集合

word(s,s) … \(\wp\)  
\(\wp.\)\(\wp X = \{ A \mid A \subset X \} \)
\(\wp0\)\(\wp \emptyset = \{ \emptyset \}\)/\(=.\)/\(\wp.\)/\(\text{set}_1.\)/\({=}{.}{.}\)◀ \(\emptyset1\)

分出公理

集合とクラスの共通部分は集合になります。が、word(sc,s)は使用できません。無限個の公理が必要なのは頭の痛い所です。
word(c,p)F … \(\text{axs}\)  
def …【\(\text{axs} ( {\sf C} )\)】≃【\(\forall {\sf x} \, \dot\exists ( {\sf x} \cap {\sf C} )\)
\(\text{nsc1}\)\(\neg \dot\exists \text{Set}\)◀ \(\text{axs} ( \text{Nsc} )\)

正則性公理

正則性公理。必要?
\(\text{axr}\)\( \forall X \neq \emptyset . \exists Y \in X . X \cap Y = \emptyset \)
axr! = axr / emp.. / cap.
\(\text{wfs}_1\)\(X \notin X\)
\(\text{wfs}_2\)\(\neg ( X \in Y \in X )\)