Statement:
\(C(\infty,\infty)\): The Axiom of Choice: Every set of non-empty sets has a choice function.
Howard_Rubin_Number: 1
Parameter(s): This form does not depend on parameters
This form's transferability is: Unknown
This form's negation transferability is: Negation Transferable
Article Citations:
Book references
Note connections:
Howard-Rubin Number | Statement | References |
---|---|---|
1 A | In every vector space, every generating set contains a basis. |
Halpern [1966]
|
1 B | Every commutative ring with unit has a maximal ideal. |
Hodges [1979]
|
1 C | For all infinite cardinals \(m\), \(UT(m,m,m)\):If every member of an infinite set \(A\) has power \(|A|\) then\(|\bigcup A| = |A|\). (Note that [1 C] implies \(m^{2} =m\) forall infinite cardinals m.) |
Howard [1994]
|
1 D | Cardinal successors 3: For every cardinal \(m\) there isa cardinal \(n\) such that \(m < n\) and \((\forall p)( m < p \rightarrow n \le p )\). |
Tarski [1954a]
Jech [1966a]
|
1 E | \(K(0)\): For every set \(S\) there is an ordinal \(\alpha\) and a one to one function \(f: S \rightarrow \alpha\). (See Form 81(\(n\))). |
|
1 F | For all ordinals \(\alpha\), \(DC(\aleph_{\alpha})\): Given a relation \(R\) such that for every subset \(Y\) of a set \(X\) with\(|Y| < \aleph_{\alpha}\), there is an \(x \in X \) with \(Y\mathrel R x\), then there is a function \(f:\aleph_{\alpha} \to X\) such that \(\forall\beta < \aleph_{\alpha}\), \(\{f(\gamma):\gamma < \beta\}\mathrel Rf(\beta)\). |
Levy [1964]
Note [133] |
1 G |
Brunner [1982a]
Note [94] |
|
1 H |
Brunner [1982a]
Note [94] |
|
1 I | In every metric space \((X,d)\) there is an\(\epsilon\)-lattice for some \(\epsilon >0\) which is not a strict upperbound of \(d\). |
Brunner [1984e]
Note [17] |
1 J |
Morris [1969]
Note [121] |
|
1 K |
|
|
1 L | Hajnal's Free Set Principle: For every set mapping \(f: X\rightarrow [X]^{<\lambda}\) where \(\lambda\) is a well orderable cardinal and \(\lambda< |X|\) there is a free set of cardinality \(|X|\). ((\([X]^{<\lambda}\) is the set of subsets of \(X\) of cardinality \(<\lambda\)). |
Brunner [1989]
Note [22] |
1 M | The ramification Lemma: If \(S: X^{\le\theta}\rightarrow {\cal P}(E)\) is a ramification system, then for each \(g \in E\) there is an \(f\) which is maximal (with respect to inclusion) in \(\{h \in X^{\le\theta}: g\in S(h)\}\). |
Brunner [1989]
Note [22] |
1 N | For every set mapping \(f: X\rightarrow [X]^{WO}\)(well ordered subsets of \(X\)) there is a co-well-orderable free subset\(H\). (\(H\) is co-well-orderable if \(X\setminus H\) is well orderable). |
Brunner [1989]
Note [22] |
1 O | \(A(D1,C)\): For every \(T_2\) topological space \((X,T)\),if \(X\) is covered by a well ordered family of closed, discrete sets theneach family \(U\subseteq T\) of pairwise disjoint sets is well ordered. |
Brunner [1983d]
Note [26] |
1 P | \(A(P)\): (Depends on \(P\) for \(P\in\{W1,W2,B1,L1,L2,S,C,H1,A1\}\)) Every \(T_2\) topological space has property \(P\). |
Brunner [1983d]
Note [26] |
1 Q | For any partial order \((X,\le)\) there is a \(\sup\) function on the bounded (above), well ordered subsets of \(X\). |
Manka [1988a]
Note [38] |
1 R | For any partial order \((X,\le)\) there is a \(\sup\) function on the bounded subsets of \(X\). |
Manka [1988a]
Note [38] |
1 S | For any partial order \((X,\le)\) if every well ordered subset of \(X\) is bounded then there is a \(\sup\) function on the well ordered subsets of \(X\). |
Manka [1988a]
Note [38] |
1 T | For every directed partial order \((X,\le)\) there is a\(\sup\) function on the bounded, well ordered subsets of \(X\). |
Manka [1988a]
Note [38] |
1 U | For every directed partial order, if every well ordered subset of \(X\) is bounded above then there is a \(\sup\) function on the well ordered subsets of \(X\). |
Manka [1988a]
Note [38] |
1 V | For every partially ordered set \((X,\le )\), if every well ordered subset is bounded above then every function \(f : X \rightarrow X\) satisfying \(\forall t\in X\), \(t\le f(t)\) has a fixed point. |
Manka [1988a]
Abian [1980]
|
1 W |
Brunner [1982a]
|
|
1 X |
Brunner [1982a]
|
|
1 Y | Refined Dual Cantor-Bernstein Theorem: If \(f : X\rightarrow Y\) and \(g : Y \rightarrow X\) are onto then there is a bijection \(h : X \rightarrow Y\) such that \(h \subseteq f \cup g^{-1}\). |
Banaschewski-Moore-1990
|
1 Z | If \((P,\le)\) is a quasi-order and \(P \neq \emptyset\) and every antichain is finite, then there is a \(P\) generic filter which is well orderable. |
Shannon [1990]
Note [47] |
1 AA | Assume \(f: S\rightarrow R\) where \(f\) is surjective and \(R\subseteq S\).Then every mapping \(g\) of \(S\) into \(R\) has the form \(g = f\circ h\) for some \(h: S \rightarrow S\). |
Smith [1982]
|
1 AB | Assume \(f: S \rightarrow R\) where \(f\) is surjective and \(R\subseteq S\).Then the mappings of \(S\) onto \(R\) are precisely the mappings of the form \(f\circ h\) where \(h: S\rightarrow S\) and \((\forall y\in R)(\exists x\in S)(h(x)\in f^{-1}(\{y\}))\). |
Smith [1982]
|
1 AC | Assume \(f: S\rightarrow R\) where \(R\subseteq S\). Then the retractions of \(S\) onto \(R\) (that is, the mappings \(g: S \rightarrow R\) which are the identity on \(R\)) are precisely the mappings \(f\circ h\) where \(h: S \rightarrow S\) and \((\forall y\in R)(h(y)\in f^{-1}(\{y\}))\). |
Smith [1982]
|
1 AD | For every class \(K\) of similar algebras \(SP^{g} K\supseteq P^{g}S\ K\). (For any class \(K\) of similar algebras, \(S\ K\) is the class of all subalgebras of elements of \(K\) (not closed under isomorphism) and \(P^{g}K\) is the class of direct products of elements of \(K\) not closed under isomorphism). |
Andreka-Nemeti-1980
|
1 AE | There is a set \(S\) such that \(SVC\) holds with \(S\) and such that \({\cal P}(S) - \{\emptyset\}\) has a choice function. Also see Form 191. |
Blass [1979]
Note [59] |
1 AF |
Blass [1979]
|
|
1 AG |
Note [60] |
|
1 AH | \(E(V,VI)\): For all infinite cardinals \(m\), \(2m = m\) implies \(m^{2} = m\). |
Howard-Yorke-1989
Note [94] |
1 AI | \(E(VI,VII)\): For all infinite cardinals \(m\), \(m^{2} = m\) implies there is an ordinal \(\alpha\) such that \(m =\aleph _{\alpha }\). |
Howard-Yorke-1989
Note [94] |
1 AJ | Let \({\cal F}\) be a family of mappings of a poset \((X,\le )\) into itself such that \(\forall f\in{\cal F}\), \(\forall x\in X\),\(f(x)\le x\). If for some element \(e\) of \(X\) each chain in \(X\) containing \(e\) has a lower bound, then the family \({\cal F}\) has a common fixed point. |
Kasahara [1976]
|
1 AK | There is an ordinal \(\beta\) such that for all cardinals \(x\), \(\alpha(x+\aleph(x), x\cdot\aleph(x))<\beta\). |
Truss [1973b]
Note [98] |
1 AL | There is an ordinal \(\beta\) such that for all cardinals\(x\), \(\alpha(x,x^2) < \beta\). |
Truss [1973b]
Note [98] |
1 AM | There is an ordinal \(\beta\) such that for no cardinal \(x\) is there a strictly increasing sequence of cardinals \(\left \{ \,y_{\gamma} : \gamma < \beta \, \right \}\) such that \(y_{\gamma}^2 = x\). |
Truss [1973b]
Note [98] |
1 AN | Every lattice \(\langle L,\cap,\cup, \subseteq\rangle\)of sets (that is, \(L\) is a family of sets and \(\cap,\ \cup\) and \(\subseteq\) are the usual operations) with a greatest element has a maximal, proper ideal. |
Bell-Fremlin-1972
|
1 AO | Any continuous surjection between compact spaces, where the range space is Hausdorff, has an irreducible restriction to a closed subset of its domain. |
Bell [1988]
Note [114] |
1 AP | For any type \(\tau\) of the form \(\tau = (M)\), everyhomomorphism of an algebra of type \(\tau\) is closed. |
Diener [1989]
Note [115] |
1 AQ | For any type \(\tau\) of the form \(\tau = (M)\), every homomorphism of an algebra A of type \(\tau\) into an algebra B of type \(\tau\) maps A onto a subalgebra of B. |
Diener [1989]
Note [105] |
1 AR | Let \(S\) be any family of disjoint non-empty sets andlet \(\tau = (\bigcup S)\), then any homomorphism from \(\frak P(\tau;\bigcup S)\)into \(\frak P(\tau;S)\) maps \(\frak P(\tau;\bigcup S)\) onto a subalgebra of \(\frak P(\tau;S)\). |
Diener [1989]
Note [115] |
1 AS | Turinici's Fixed Point Theorem: If \((X,\le)\) is a directed, partially ordered set and \(\tau\) is a topology on \(X\) such that
|
Manka [1988b]
Note [38] |
1 AT | For all cardinal numbers \(\kappa_1\) and \(\kappa_2\), if a graph is both \(\kappa_1\) and \(\kappa_2\) colorable then it is also\(\kappa\) colorable for some \(\kappa\) such that \(\kappa\le^*\kappa_1\) and \(\kappa\le^*\kappa_2\). (\(\le^*\) is the surjective cardinal ordering). |
Komj'ath-Galvin-1991
|
1 AU | Every graph has an irreducible, good coloring. |
Komj'ath-Galvin-1991
Note [118] |
1 AV | Every graph of the form \(G(A,H(A))\) has an irreducible, good coloring. (\(H\) is the Hartogs aleph function.) |
Komj'ath-Galvin-1991
Note [118] |
1 AW | Every graph has a chromatic number. |
Komj'ath-Galvin-1991
Note [118] |
1 AX | Birkhoff Representation Theorem: Every algebra isisomorphic to a subdirect product of subdirectly irreducible algebras. |
Birkhoff [1944]
Gratzer [1986]
Book: Universal Algebra [1979] |
1 AY | For each \(\lambda\in\Lambda\) let \(S_\lambda\) be a subset of some topological space \(X_\lambda\). Then |
Schechter [1992]
|
1 AZ | For each \(\lambda\in\Lambda\), let \(X_\lambda\) be a complete uniform space. Then, the product \(\prod_{\lambda\in\Lambda}X_\lambda\) equipped with the product uniform structure, is also complete.(See, for example, Kelley [1955] pp 176ff for definitions.) |
Schechter [1992]
Book: General Topology |
1 BA | (Depends on the prime \(p\)) Every group has a maximal \(p\)-subgroup. |
Howard-Yorke-1987
Note [24] |
1 BB | Strong Nielsen-Schreier Theorem II: If \(G\) is a group which is freely generated by \(X\) and \(U\) is a subgroup of \(G\),then there is a subset \(A\) of \(G\) which freely generates \(U\) and is level with respect to \(X\). |
Howard [1985]
Note [129] |
1 BC | Assume \(P\) is a partially ordered set in which every non-empty chain has an upper bound and \(f: P\to P\) satisfies \(\forall x\in f(P) \cup \{\,a\in P : a\) is an upper bound for some chain in \(f(P)\,\}\),\(x\le f(f(x))\). Then \(f\) has a fixed apex \(u\) (that is, there is some \(v\in P\) such that \(f(u)=v\) and \(f(v)=u\).) |
Taskovi'c [1988]
Taskovi'c [1992a]
|
1 BD | Let \(P\) be a partially ordered set in which every increasing sequence has an upper bound and \(f:P\to P\) satisfies \(x \le f(f(x))\) for all \(x\in f(P) \cup \{x\in P : x\) is an upper bound for some increasing sequence in \(f(P)\}\). Then \(f\) has a fixed apex \(u\)(that is, \(\exists v\in P\), such that \(f(u) = v\) and \(f(v) = u\)). (For purposes of [1 BD], ``sequence'' means a function whose domain is an ordinal.) |
Taskovi'c [1992b]
|
1 BE | Every unique factorization domain can be mapped homomorphically onto a non-zero subdirectly irreducible ring. Gratzer [1979] pp 122-124. |
Rav [1988]
Note [84] Book: Universal Algebra [1979] |
1 BF | (\(DT_0)\): Every topological space \(X\) has a \(T_0\) subspace that is dense in \(X\). (\(Y\) is dense in \(X\) if there is no non-empty open subset \(O\subseteq X\) such that \(O\cap Y=\emptyset\).) |
McCarten [1988]
Note [106] |
1 BG | (C\(T_0\)): Every topological space \(X\) has a \(T_0\)subspace that is codense in \(X\). (\(Y\) is codense in \(X\) if there is nonon-empty closed subset \(C\subseteq X\) such that \(C\cap Y=\emptyset\).) |
McCarten [1988]
Note [106] |
1 BH | \((TT_0)\): Every topological space \(X\) has a \(T_0\) subspace that is thick in \(X\). (\(Y\) is thick in \(X\) if there is nonon-empty open and closed (clopen) subset \(H\subseteq X\) such that\(H\cap Y=\emptyset\).) |
McCarten [1988]
Note [106] |
1 BI | \((MT_0)\): Every topological space has a maximal \(T_0\)subspace. |
Schnare [1968]
Note [106] |
1 BJ | In every vector space over the two element field, every generating set contains a basis. |
Keremedis [1996a]
|
1 BK | Every open cover \(\cal{U}\) of a metric space \((X,d)\) can be written as a well ordered union \(\bigcup\{U_\alpha :\alpha\in\gamma\}\) where \(\gamma\) is an ordinal and each \(U_\alpha\) is pairwise disjoint. Howard/Keremedis/Rubin/Stanley [1999]. |
|
1 BL | Every family of closed sets in a \(T_2\) topological space includes a maximal subfamily with the finite intersectionproperty. H.Rubin/J.Rubin [1985], p 60, \(M14\). |
Keremedis [1998a]
Book: Equivalents of the Axiom of Choice II |
1 BM | For every family \(\{(X_i,T_i): i\in k\}\) of \(T_1\) topological spaces, the box topology contains an element \(\prod_{i\in k}O_i\), such that \(\emptyset\ne O_i\) and \(O_i\ne X_i\) for all \(i\in k\). |
Keremedis [1998a]
Note [77] |
1 BN | For every family \(\{(X_i,T_i): i\in k\}\) of disjoint \(T_1\) topological spaces, the free union contains an open set \(O\) such that \(\emptyset\ne O\cap X_i\) and \( O\cap X_i\ne X_i\) for all\(i\in k\). |
Keremedis [1998a]
Note [77] |
1 BO | For every \(T_1\) topological space \((X,T)\) and every base (subbase) \(B\) for \(X\) there exists a \(\subseteq\)-maximal cellular family \(Q\subseteq B\). |
Keremedis [1998a]
Note [77] |
1 BP | For every dense in itself topological space \((X, T)\) and every base \(B\) for \(X\) there exists a nest \(N\) included in \(B\). |
Keremedis [1998a]
Note [77] |
1 BQ | For every dense in itself topological space \((X,T)\) and every base \(B\) for \(X\) there exists a tower \(R\) included in \(B\). |
Keremedis [1998a]
Note [77] |
1 BR | For every \(T_2\) space \((X,T)\) and every subbase \(\cal B\) for \(X\), if \(\cal C\) and \(\cal D\) are cellular families of \(X\) included in \(\cal B\), then there is a cellular family \(\cal E\subseteq\cal B\) such that \(\cal C\) and \(\cal D\) are equipollent to subsets of\(\cal E\). |
Keremedis [1998a]
Note [77] |
1 BS | For every Abelian group \((G,+)\), for every \(H \subseteq G\), the infinite system of equations \[x_i + y_i = a_i,\ i\in I,\ a_i\in G\] has a solution in \(H\) iff each of its equations has a solution in \(H\). |
Keremedis [1996b]
|
1 BT | For every Boolean ring \((B,+,\cdot)\) and every \(H \subseteq B\) which is closed under \(+\) there exists a \(\subseteq\)-maximal ideal \(Q\subseteq B\) such that \(H\cap Q=\{0\}\). |
Keremedis [1996b]
|
1 BU | In every vector space over \({\Bbb Q}\), every generating set includes a basis. |
Blass [1984a]
Note [137] |
1 BV | If \((X,T)\) is a \(T_4\) topological space and \(G =\{G_i: i\in K\}\), \(|G_i|\ge 2\), is a locally finite family of compact sets with non-empty pairwise disjoint interiors, then there is a continuous real valued function \(f\) on \(X\) which assumes at least two distinct values on each \(G_i\). |
Keremedis [1997]
Note [43] |
1 BW | If \((X,T)\) is a \(T_4\) topological space and \(U =\{U_i: i\in K\}\), \(|U_i|\ge 2\), is a locally finite family ofopen non-empty pairwise disjoint sets, then there is a continuous real valued function \(f\) on \(X\) which assumes at least two distinct values on each \(U_i\). |
Keremedis [1997]
Note [43] |
1 BX | For every Abelian group \(G\) and every subgroup \(H\) of \(G\) there exists a set of representatives for the quotient \(G/H\). |
Keremedis [1996b]
|
1 BY | If \(x\) is a set of sets of cardinality at least 2, then there exists a function \(f\) such that for each \(u\in x\), \(f(u)\) is a finite, non-empty, proper subset of \(u\). (Form [1 BY] implies [62 E] (\(KW(\infty,<\aleph_0)\)) and Form 67 (MC) and Form 62 \(+\) Form 67 \(\to\) AC.) |
Blass [1979]
|
1 BZ | Vector Space Multiple Choice: For every family \(V = \{\,V_i : i \in K\,\}\) of non-trivial vector spaces there is a family \(F = \{\, F_i : i\in K\,\}\) such that for each \(i\in K\),\(F_i\) is a non-empty, finite, independent subset of \(V_i\). |
Note [127] |
1 CA | Strong Nielsen-Schreier Theorem I: If \(G\) is a groupwhich is freely generated by \(X\) and \(U\) is a subgroup of \(G\), then there is a subset \(A\) of \(G\) which freely generates \(U\) and has the Nielsen property with respect to \(X\). |
Howard [1985]
Note [129] |
1 CB | For every infinite cardinal \(\kappa\), if \((X,T)\) is a \(T_2\) space having a base \(B\) such that no \(Q\subseteq B\), \(|Q| <\kappa\), is a tower, then for every family \(\cal D=\{D_i:i\in\kappa\}\) of dense open sets of \(X\) there is a filter \(F\subseteq T\) such thatfor every \(i\in\kappa\) there is a \(b\in F\) with \(b\subseteq D_i\). |
Keremedis [1998a]
Note [77] |
1 CC | \(PC(\aleph_0,\hbox{odd},\infty)\) +\(MC_{\omega^+}\). \(PC(\aleph_0,\hbox{odd},\infty)\) is ``Every denumerable family of odd sized (finite) sets has an infinite subfamily with a choice function.'' and \(MC_{\omega^+}\)is ``For every natural number \(n \ge 1\) and forevery set of non-empty sets, there is a function \(f\) such that for each \(u\in x\), \(f(u)\) is a non-empty finite subset of \(u\) suchthat \(|f(u)|\) and \(n\) are relatively prime.'' |
Note [133] |
1 CD |
In a commutative ring, every proper ideal can be extended to a maximal ideal. ([1 CD] implies |
Krull [1929]
|
1 CE | Every open cover \(\cal{U}\) of a metric space \((X,d)\)can be written as a well ordered union \(\bigcup\{U_\alpha :\alpha\in\gamma\}\) where \(\gamma\) is an ordinal and each \(U_\alpha\) is discrete. Howard/Keremedis/Rubin/Stanley [1999] . |
Note [141] |
1 CF | If a topological space is \(cwH\), then it is \(cwH(B)\)for every basis \(B\). |
Howard-Rubin-Keremedis-Rubin-1998b
Note [141] |
1 CG | The disjoint union of \(cwH\) spaces is \(cwH(B)\) for every basis \(B\). |
Howard-Rubin-Keremedis-Rubin-1998b
Note [141] |
1 CH | If a topological space is \(cwN\), then it is \(cwH(B)\) for any basis \(B\). |
Howard-Rubin-Keremedis-Rubin-1998b
Note [141] |
1 CI | Every compact space is A-U compact. |
Herrlich [1996a]
Howard [1990]
Note [6] |
1 CJ | Every B compact Hausdorff space is A-U compact. |
Herrlich [1996a]
Note [6] |
1 CK | Products of A-U compact (Hausdorff) spacesare A-U compact. Herrlich [1996a] and Note 6. |
|
1 CL | Finite products of A-U compact spaces are A-Ucompact. Herrlich [1996a] and Note 6. |
|
1 CM | Spaces with finite topologies are A-U compact.Herrlich [1996a] and Note 6. |
|
1 CN | Products of spaces with finite topologies arecompact. Alas [1969]. |
|
1 CO(X,Y) | The product of \(X\) spaces is \(Y\),where \(X\) is either ``compact'', ``S-B compact'', or ``linearly compact''and \(Y\) is either ''compact'' or ``S-B compact''. Howard [1990] and Note 6. |
|
1 CP | Form 384 +Form 8. Herrlich/Steprans [1997]. |
|
1 CQ | Closed Filter Extendability for \(T_0\) Spaces.Every closed filter in a \(T_0\) topological space can be extended toa maximal closed filter. Keremedis/Tachtsis [1999b] and note10. |
|
1 CR | The Ascoli Theorem for A-U compactness. See form[14 CU], Note 6 and Herrlich [1997c] |
|
1 CS | Every W compact pseudometric space is A-U compact.See Howard [1990] (the proof of Theorem 3) and Note 6. |
|
1 CT | Every sequentially compact pseudometric space isA-U compact. Herrlich [1997a] |
|
1 CU | Products of topological spaces with finite topologiesare A-U compact. Herrlich [1997a] and Note 6. |
|
1 CV | Products of finite discrete topological spaces areA-U compact. Herrlich [1996a] and Note 6. |
|
1 CW | Every closed (open) filter in a \(T_1\) topologicalspace extends to a maximal closed (open) filter with a well orderablefilter base. Keremedis/Tachtsis [2000]. |
|
1 CX | For every set \(A\ne\emptyset\), every filter $\cal F\subseteq \cal P(A)$ extends to an ultrafilter with a well orderablefilter base. Keremedis/Tachtsis [2000]. |
|
1 CY | Every partial function on a set \(A\) can bedefined as follows: Let \(\varrho\), \(\sigma\), \(\varphi\), \(\tau_1\),\(\tau_2\), \(\tau_3\) be equivalence relations on \(A\) such that \(\sigma\)has a distinguished equivalence class \(D\) which is a set of distinctrepresentatives for the equivalence classes of \(\varrho\), \(\varphi\)has at most three equivalence classes \(D_1\), \(D_2\), and \(D_3\), andthe equivalence classes of \(\tau_n\), \(n=1,2,3\), have at most twoelements. If \(x\in A\) has a \(\varrho\)-representative \(u\in D\) andthere is an \(n=1,2,3\) such that \(u\in D_n\), then choose the smallest \(n\)with this property and define \(f(x)=u\), where \(\{u,f(x)\}\in D_n\).Armbrust [1986]. |
|
1 CZ | Every compact frame has a maximal element.Banaschewski [1990] and Note 29. |
|
1 DA | Every large subspace of the spectrum of acompact frame is compact. (A subspace is large if it containsall minimal elements.) Banaschewski [1990] and Note 29. |
|
1 DB | Any large homomorphic image of a compact frameis compact. (A frame homomorphism \(\phi: L\to M\) is calledlarge if \(\phi(s) < e\) (the unit) for all maximal elements\(s\in L\).) Banaschewski [1990] and Note 29. |
|
1 DC | In any complete lattice with at least two elementsthere exists an ultrafilter. Banaschewski [1961]. |
|
1 DD | If \((L_i)_{i\in I}\) is a family of completelattices, each of which has at least two elements, then there existsa family \((M_i)_{i\in I}\) of filters such that \(M_i\) is anultrafilter in \(L_i\). Banaschewski [1961]. |
|
1 DE | Let \(L\) be a complete distributive lattice withat least two elements and let \(A\) be a proper subset of \(L\) such thatfor all \(x\in L\) and \(a\in A\), \(x\le a\) implies \(x\in a\). Then thereis an ultrafilter \(M\) disjoint form \(A\). Banaschewski [1961]. |
|
1 DF | For any set \(X\), if \(\cal C\) is a set ofconditionally \(\cap\)-closed subsets of \(\cal P(X)\), then \(\cal C\)contains a maximal filter (not necessarily proper). (If $\cal C\subseteq\cal P(X)\(, \)\cal C\( is called conditionally \)\cap$-closed if forall \(A\), \(B\), \(C\) in \(\cal C\), \(C\subseteq A\cap B\) implies $A\cap B\in\cal C$.) Banaschewski [1961]. |
|
1 DG | Vector Space Kinna-Wagner Principle: For every family \(V = \{V_i : i \in K\}\) of non-trivial vector spaces there is a family \(F = \{F_i : i\in K\}\) such that for each \(i\in K\), \(F_i\) is a non-empty, independent subset of \(V_i\). |
Keremedis [2001a]
Note [127] |
1 DH | Every complete lattice is constructively complete. \ac{Ern\'e} \cite{2000} |
Note [154] |
1 DI-$Z$ | (Where \(\cal Z\) is a subset selection such that for all partial orders \((P,\le)\), \(\cal E P\subseteq \cal Z P\subseteq \cal D P\).) Every complete lattice is \(\cal Z^\lor\)-constructively complete. \ac{Ern\'e} \cite{2000}. |
Note [154] |
1 DJ | Every directed partially ordered set is constructively directed. \ac{Ern\'e} \cite{2000}. |
Note [154] |
1 DK | For all \(X\), if \(X\neq\emptyset\), then there is a binary operation on \(X\) that makes \(X\) a group. Rubin, H./Rubin, J. [1985], p.110, AL14}. |
Hickman [1976]
Book: Equivalents of the Axiom of Choice II |