Empty Set Rewrite Rules

Rules that are marked with a * in the first column are implemented in the latest version of Rodin. Rules without a * are planned to be implemented in future versions. Other conventions used in these tables are described in The_Proving_Perspective_(Rodin_User_Manual)#Rewrite_Rules.

All rewrite rules that match the pattern $\textbf{P}=\emptyset$ are also applicable to predicates of the form $\textbf{P}\subseteq\emptyset$ and $\emptyset=\textbf{P}$, as these predicates are equivalent.

	Name	Rule	Side Condition	A/M
*	DEF_SPECIAL_NOT_EQUAL	$\lnot\, S = \emptyset \;\;\defi\;\; \exists x \qdot x \in S$	where $x$ is not free in $S$	M
	SIMP_SETENUM_EQUAL_EMPTY	$\{ A, \ldots , B\} = \emptyset \;\;\defi\;\; \bfalse$		A
*	SIMP_SPECIAL_EQUAL_COMPSET	$\{ x \qdot P(x) \mid E \} = \emptyset \;\;\defi\;\; \forall x\qdot \lnot\, P(x)$		A
	SIMP_BINTER_EQUAL_TYPE	$A \binter \ldots \binter B = \mathit{Ty} \;\;\defi\;\; A = \mathit{Ty} \land \ldots \land B = \mathit{Ty}$	where $\mathit{Ty}$ is a type expression	A
	SIMP_BUNION_EQUAL_EMPTY	$A \bunion \ldots \bunion B = \emptyset \;\;\defi\;\; A = \emptyset \land \ldots \land B = \emptyset$		A
	SIMP_SETMINUS_EQUAL_EMPTY	$A \setminus B = \emptyset \;\;\defi\;\; A \subseteq B$		A
	SIMP_SETMINUS_EQUAL_TYPE	$A \setminus B = \mathit{Ty} \;\;\defi\;\; A = \mathit{Ty} \land B = \emptyset$	where $\mathit{Ty}$ is a type expression	A
	SIMP_POW_EQUAL_EMPTY	$\pow (S) = \emptyset \;\;\defi\;\; \bfalse$		A
	SIMP_POW1_EQUAL_EMPTY	$\pown (S) = \emptyset \;\;\defi\;\; S = \emptyset$		A
	SIMP_KINTER_EQUAL_TYPE	$\inter (S) = \mathit{Ty} \;\;\defi\;\; S = \{ \mathit{Ty} \}$	where $\mathit{Ty}$ is a type expression	A
	SIMP_KUNION_EQUAL_EMPTY	$\union (S) = \emptyset \;\;\defi\;\; S \subseteq \{ \emptyset \}$		A
	SIMP_QINTER_EQUAL_TYPE	$(\Inter x\qdot P(x) \mid E(x)) = \mathit{Ty} \;\;\defi\;\; \forall x\qdot P(x) \limp E(x) = \mathit{Ty}$	where $\mathit{Ty}$ is a type expression	A
	SIMP_QUNION_EQUAL_EMPTY	$(\Union x\qdot P(x) \mid E(x)) = \emptyset \;\;\defi\;\; \forall x\qdot P(x) \limp E(x) = \emptyset$		A
	SIMP_NATURAL_EQUAL_EMPTY	$\nat = \emptyset \;\;\defi\;\; \bfalse$		A
	SIMP_NATURAL1_EQUAL_EMPTY	$\natn = \emptyset \;\;\defi\;\; \bfalse$		A
*	SIMP_TYPE_EQUAL_EMPTY	$\mathit{Ty} = \emptyset \;\;\defi\;\; \bfalse$	where $\mathit{Ty}$ is a type expression	A
	SIMP_CPROD_EQUAL_EMPTY	$S \cprod T = \emptyset \;\;\defi\;\; S = \emptyset \lor T = \emptyset$		A
	SIMP_CPROD_EQUAL_TYPE	$S \cprod T = \mathit{Ty} \;\;\defi\;\; S = \mathit{Ta} \land T = \mathit{Tb}$	where $\mathit{Ty}$ is a type expression equal to $\mathit{Ta} \cprod \mathit{Tb}$	A
	SIMP_UPTO_EQUAL_EMPTY	$i \upto j = \emptyset \;\;\defi\;\; i > j$		A
	SIMP_UPTO_EQUAL_INT	$i \upto j = \intg \;\;\defi\;\; \bfalse$		A
*	SIMP_SPECIAL_EQUAL_REL	$A \rel B = \emptyset \;\;\defi\;\; \bfalse$	idem for operators $\pfun \pinj$	A
	SIMP_TYPE_EQUAL_REL	$A \rel B = \mathit{Ty} \;\;\defi\;\; A = \mathit{Ta} \land B = \mathit{Tb}$	where $\mathit{Ty}$ is a type expression equal to $\mathit{Ta} \cprod \mathit{Tb}$	A
*	SIMP_SPECIAL_EQUAL_RELDOM	$A \trel B = \emptyset \;\;\defi\;\; \lnot\, A = \emptyset \land B = \emptyset$	idem for operator $\tfun$	A
	SIMP_TYPE_EQUAL_RELDOM	$A \trel B = \mathit{Ty} \;\;\defi\;\; \bfalse$	where $\mathit{Ty}$ is a type expression, idem for operator $\srel, \strel, \tfun, \tinj, \tsur, \tbij$	A
	SIMP_SREL_EQUAL_EMPTY	$A \srel B = \emptyset \;\;\defi\;\; A = \emptyset \land \lnot\,B = \emptyset$		A
	SIMP_STREL_EQUAL_EMPTY	$A \strel B = \emptyset \;\;\defi\;\; (A = \emptyset \leqv \lnot\,B = \emptyset)$		A
	SIMP_DOM_EQUAL_EMPTY	$\dom (r) = \emptyset \;\;\defi\;\; r = \emptyset$		A
	SIMP_RAN_EQUAL_EMPTY	$\ran (r) = \emptyset \;\;\defi\;\; r = \emptyset$		A
	SIMP_FCOMP_EQUAL_EMPTY	$p \fcomp q = \emptyset \;\;\defi\;\; \ran (p) \binter \dom (q) = \emptyset$		A
	SIMP_BCOMP_EQUAL_EMPTY	$p \bcomp q = \emptyset \;\;\defi\;\; \ran (q) \binter \dom (p) = \emptyset$		A
	SIMP_DOMRES_EQUAL_EMPTY	$S \domres r = \emptyset \;\;\defi\;\; \dom (r) \binter S = \emptyset$		A
	SIMP_DOMRES_EQUAL_TYPE	$S \domres r = \mathit{Ty} \;\;\defi\;\; S = \mathit{Ta} \land r = \mathit{Ty}$	where $\mathit{Ty}$ is a type expression equal to $\mathit{Ta} \cprod \mathit{Tb}$	A
	SIMP_DOMSUB_EQUAL_EMPTY	$S \domsub r = \emptyset \;\;\defi\;\; \dom (r) \subseteq S$		A
	SIMP_DOMSUB_EQUAL_TYPE	$S \domsub r = \mathit{Ty} \;\;\defi\;\; S = \emptyset \land r = \mathit{Ty}$	where $\mathit{Ty}$ is a type expression	A
	SIMP_RANRES_EQUAL_EMPTY	$r \ranres S = \emptyset \;\;\defi\;\; \ran (r) \binter S = \emptyset$		A
	SIMP_RANRES_EQUAL_TYPE	$r \ranres S = \mathit{Ty} \;\;\defi\;\; S = \mathit{Tb} \land r = \mathit{Ty}$	where $\mathit{Ty}$ is a type expression equal to $\mathit{Ta} \cprod \mathit{Tb}$	A
	SIMP_RANSUB_EQUAL_EMPTY	$r \ransub S = \emptyset \;\;\defi\;\; \ran (r) \subseteq S$		A
	SIMP_RANSUB_EQUAL_TYPE	$r \ransub S = \mathit{Ty} \;\;\defi\;\; S = \emptyset \land r = \mathit{Ty}$	where $\mathit{Ty}$ is a type expression	A
	SIMP_CONVERSE_EQUAL_EMPTY	$r^{-1} = \emptyset \;\;\defi\;\; r = \emptyset$		A
	SIMP_CONVERSE_EQUAL_TYPE	$r^{-1} = \mathit{Ty} \;\;\defi\;\; r = \mathit{Ty}^{-1}$	where $\mathit{Ty}$ is a type expression	A
	SIMP_RELIMAGE_EQUAL_EMPTY	$r[S] = \emptyset \;\;\defi\;\; S \domres r = \emptyset$		A
	SIMP_OVERL_EQUAL_EMPTY	$r \ovl \ldots \ovl s = \emptyset \;\;\defi\;\; r = \emptyset \land \ldots \land s = \emptyset$		A
	SIMP_DPROD_EQUAL_EMPTY	$p \dprod q = \emptyset \;\;\defi\;\; \dom (p) \binter \dom (q) = \emptyset$		A
	SIMP_DPROD_EQUAL_TYPE	$p \dprod q = \mathit{Ty} \;\;\defi\;\; p = \mathit{Ta} \cprod \mathit{Tb} \land q = \mathit{Ta} \cprod \mathit{Tc}$	where $\mathit{Ty}$ is a type expression equal to $\mathit{Ta} \cprod (\mathit{Tb} \cprod \mathit{Tc})$	A
	SIMP_PPROD_EQUAL_EMPTY	$p \pprod q = \emptyset \;\;\defi\;\; p = \emptyset \lor q = \emptyset$		A
	SIMP_PPROD_EQUAL_TYPE	$p \pprod q = \mathit{Ty} \;\;\defi\;\; p = \mathit{Ta} \cprod \mathit{Tb} \land q = \mathit{Tc} \cprod \mathit{Td}$	where $\mathit{Ty}$ is a type expression equal to $(\mathit{Ta} \cprod \mathit{Tb}) \cprod (\mathit{Tc} \cprod \mathit{Td})$	A
	SIMP_ID_EQUAL_EMPTY	$\id = \emptyset \;\;\defi\;\; \bfalse$		A
	SIMP_PRJ1_EQUAL_EMPTY	$\prjone = \emptyset \;\;\defi\;\; \bfalse$		A
	SIMP_PRJ1_EQUAL_TYPE	$\prjone = \mathit{Ty} \;\;\defi\;\; \finite(\mathit{Ta}) \land \card(\mathit{Ta})=1$	where $\mathit{Ty}$ is a type expression equal to $\mathit{Ta} \cprod \mathit{Tb} \cprod \mathit{Ta}$	A
	SIMP_PRJ2_EQUAL_EMPTY	$\prjtwo = \emptyset \;\;\defi\;\; \bfalse$		A
	SIMP_PRJ2_EQUAL_TYPE	$\prjtwo = \mathit{Ty} \;\;\defi\;\; \finite(\mathit{Tb}) \land \card(\mathit{Tb})=1$	where $\mathit{Ty}$ is a type expression equal to $\mathit{Ta} \cprod \mathit{Tb} \cprod \mathit{Tb}$	A