Statement List for Metamath Proof Explorer - 2201-2300 - Page 23 of 107
| Type | Label | Description |
| Statement |
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| Theorem | unssi 2201 |
An inference that the union of two subclasses is a subclass.
(Contributed by Raph Levien, 10-Dec-2002.)
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| Theorem | ssun 2202 |
A condition that implies inclusion in the union of two classes.
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| Theorem | elin 2203 |
Expansion of membership in an intersection of two classes. Theorem 12
of [Suppes] p. 25.
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| Theorem | incom 2204 |
Commutative law for intersection of classes. Exercise 7 of
[TakeutiZaring] p. 17.
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| Theorem | ineqri 2205 |
Inference from membership to intersection.
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| Theorem | ineq1 2206 |
Equality theorem for intersection of two classes.
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| Theorem | ineq2 2207 |
Equality theorem for intersection of two classes.
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| Theorem | ineq12 2208 |
Equality theorem for intersection of two classes.
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| Theorem | ineq1i 2209 |
Equality inference for intersection of two classes.
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| Theorem | ineq2i 2210 |
Equality inference for intersection of two classes.
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| Theorem | ineq12i 2211 |
Equality inference for intersection of two classes. (The proof was
shortened by Eric Schmidt, 26-Jan-2007.)
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| Theorem | ineq1d 2212 |
Equality deduction for intersection of two classes.
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| Theorem | ineq2d 2213 |
Equality deduction for intersection of two classes.
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| Theorem | ineq12d 2214 |
Equality deduction for intersection of two classes.
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| Theorem | ineqan12d 2215 |
Equality deduction for intersection of two classes.
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| Theorem | hbin 2216 |
Bound-variable hypothesis builder for the intersection of classes.
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| Theorem | rabbirdv 2217 |
Deduction from wff to restricted class abstraction.
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| Theorem | inidm 2218 |
Idempotent law for intersection of classes. Theorem 15 of [Suppes]
p. 26.
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| Theorem | inass 2219 |
Associative law for intersection of classes. Exercise 9 of
[TakeutiZaring] p. 17.
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| Theorem | in12 2220 |
A rearrangement of intersection.
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| Theorem | in23 2221 |
A rearrangement of intersection.
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| Theorem | in4 2222 |
Rearrangement of intersection of 4 classes.
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| Theorem | inindi 2223 |
Intersection distributes over itself.
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| Theorem | inindir 2224 |
Intersection distributes over itself.
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| Theorem | sseqin2 2225 |
A relationship between subclass and intersection. Similar to
Exercise 9 of [TakeutiZaring] p.
18.
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| Theorem | inss1 2226 |
The intersection of two classes is a subset of one of them. Part of
Exercise 12 of [TakeutiZaring] p.
18.
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| Theorem | inss2 2227 |
The intersection of two classes is a subset of one of them. Part of
Exercise 12 of [TakeutiZaring] p.
18.
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| Theorem | ssin 2228 |
Subclass of intersection. Theorem 2.8(vii) of [Monk1] p. 26.
|
 
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| Theorem | ssini 2229 |
An inference showing that the a subclass of two classes is a subclass of
their intersection.
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| Theorem | ssrin 2230 |
Add right intersection to subclass relation.
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| Theorem | sslin 2231 |
Add left intersection to subclass relation.
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| Theorem | ss2in 2232 |
Intersection of subclasses.
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| Theorem | ssinss1 2233 |
Intersection preserves subclass relationship.
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| Theorem | unabs 2234 |
Absorption law for union.
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| Theorem | inabs 2235 |
Absorption law for intersection.
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| Theorem | nssinpss 2236 |
Negation of subclass expressed in terms of intersection and proper
subclass.
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| Theorem | nsspssun 2237 |
Negation of subclass expressed in terms of proper subclass and union.
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| Theorem | dfss4 2238 |
Subclass defined in terms of class difference. See comments under
dfun2 2239.
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| Theorem | dfun2 2239 |
An alternate definition of the union of two classes in terms of class
difference, requiring no dummy variables. Along with dfin2 2240 and
dfss4 2238 it shows we can express union, intersection,
and subset directly
in terms of the single "primitive" operation (class
difference).
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| Theorem | dfin2 2240 |
An alternate definition of the intersection of two classes in terms of
class difference, requiring no dummy variables. See comments under
dfun2 2239. Another version is given by dfin4 2244.
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| Theorem | difin 2241 |
Difference with intersection. Theorem 33 of [Suppes] p. 29.
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| Theorem | dfun3 2242 |
Union defined in terms of intersection (DeMorgan's law). Definition of
union in [Mendelson] p. 231.
|
 
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| Theorem | dfin3 2243 |
Intersection defined in terms of union (DeMorgan's law. Similar to
Exercise 4.10(n) of [Mendelson] p. 231.
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| Theorem | dfin4 2244 |
Alternate definition of the intersection of two classes. Exercise 4.10(q)
of [Mendelson] p. 231.
|
 
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| Theorem | invdif 2245 |
Intersection with universal complement. Remark in [Stoll] p. 20.
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| Theorem | indif 2246 |
Intersection with class difference. Theorem 34 of [Suppes] p. 29.
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| Theorem | indi 2247 |
Distributive law for intersection over union. Exercise 10 of
[TakeutiZaring] p. 17.
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| Theorem | undi 2248 |
Distributive law for union over intersection. Exercise 11 of
[TakeutiZaring] p. 17.
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| Theorem | indir 2249 |
Distributive law for intersection over union. Theorem 28 of [Suppes]
p. 27.
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| Theorem | undir 2250 |
Distributive law for union over intersection. Theorem 29 of [Suppes]
p. 27.
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| Theorem | unineq 2251 |
Infer equality from equalities of union and intersection. Exercise 20
of [Enderton] p. 32 and its converse.
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| Theorem | uneqin 2252 |
Equality of union and intersection implies equality of their arguments.
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| Theorem | difundi 2253 |
Distributive law for class difference. Theorem 39 of [Suppes] p. 29.
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| Theorem | difundir 2254 |
Distributive law for class difference.
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| Theorem | difindi 2255 |
Distributive law for class difference. Theorem 40 of [Suppes] p. 29.
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| Theorem | difindir 2256 |
Distributive law for class difference.
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| Theorem | undm 2257 |
DeMorgan's law for union. Theorem 5.2(13) of [Stoll] p. 19.
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| Theorem | indm 2258 |
DeMorgan's law for intersection. Theorem 5.2(13') of [Stoll] p. 19.
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| Theorem | difun1 2259 |
A relationship involving double difference and union.
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| Theorem | dif23 2260 |
Swap second and third argument of double difference.
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| Theorem | symdif1 2261 |
Two ways to express symmetric difference. This theorem shows the
equivalence of the definition of symmetric difference in [Stoll] p. 13
and the restated definition in Example 4.1 of [Stoll] p. 262.
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| Theorem | symdif2 2262 |
Two ways to express symmetric difference.
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| Theorem | unab 2263 |
Union of two class abstractions.
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| Theorem | inab 2264 |
Intersection of two class abstractions.
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| Theorem | difab 2265 |
Difference of two class abstractions.
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| Theorem | unrab 2266 |
Union of two restricted class abstractions.
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| Theorem | inrab 2267 |
Intersection of two restricted class abstractions.
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| Theorem | inrab2 2268 |
Intersection with a restricted class abstraction.
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| Theorem | difrab 2269 |
Difference of two restricted class abstractions.
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| Theorem | |