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Change filters for methods to increase their rank #1170

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12 changes: 6 additions & 6 deletions doc/cong.xml
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Expand Up @@ -556,17 +556,17 @@ gap> cong := SemigroupCongruence(S, [Transformation([1, 2, 1]),
> Transformation([2, 1, 2])]);;
gap> classes := NonTrivialEquivalenceClasses(cong);;
gap> Set(classes);
[ <2-sided congruence class of Transformation( [ 1, 2, 2 ] )>,
<2-sided congruence class of Transformation( [ 3, 1, 1 ] )>,
<2-sided congruence class of Transformation( [ 3, 1, 3 ] )>,
[ <2-sided congruence class of Transformation( [ 3, 3, 3 ] )>,
<2-sided congruence class of Transformation( [ 2, 1, 2 ] )>,
<2-sided congruence class of Transformation( [ 3, 3, 3 ] )> ]
<2-sided congruence class of Transformation( [ 1, 2, 2 ] )>,
<2-sided congruence class of Transformation( [ 3, 1, 3 ] )>,
<2-sided congruence class of Transformation( [ 3, 1, 1 ] )> ]
gap> cong := RightSemigroupCongruence(S, [Transformation([1, 2, 1]),
> Transformation([2, 1, 2])]);;
gap> classes := NonTrivialEquivalenceClasses(cong);;
gap> Set(classes);
[ <right congruence class of Transformation( [ 3, 1, 3 ] )>,
<right congruence class of Transformation( [ 2, 1, 2 ] )> ]]]></Example>
[ <right congruence class of Transformation( [ 2, 1, 2 ] )>,
<right congruence class of Transformation( [ 3, 1, 3 ] )> ] ]]></Example>
</Description>
</ManSection>
<#/GAPDoc>
Expand Down
22 changes: 1 addition & 21 deletions gap/libsemigroups/cong.gi
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Expand Up @@ -292,27 +292,6 @@ end);

# Methods for congruence classes

InstallMethod(\<,
"for congruence classes of CanUseLibsemigroupsCongruence", IsIdenticalObj,
[IsLeftRightOrTwoSidedCongruenceClass, IsLeftRightOrTwoSidedCongruenceClass],
1, # to beat the method in congruences/cong.gi for
# IsLeftRightOrTwoSidedCongruenceClass
function(class1, class2)
local C, word1, word2;

C := EquivalenceClassRelation(class1);
if not CanUseLibsemigroupsCongruence(C)
or not HasGeneratingPairsOfLeftRightOrTwoSidedCongruence(C) then
TryNextMethod();
elif C <> EquivalenceClassRelation(class2) then
return false;
fi;

word1 := Factorization(Range(C), Representative(class1));
word2 := Factorization(Range(C), Representative(class2));
return CongruenceReduce(C, word1) < CongruenceReduce(C, word2);
end);

InstallMethod(EquivalenceClasses,
"for CanUseLibsemigroupsCongruence with known generating pairs",
[CanUseLibsemigroupsCongruence and
Expand Down Expand Up @@ -405,3 +384,4 @@ function(cong, elm)
# Shouldn't be able to reach here
Assert(0, false);
end);

4 changes: 3 additions & 1 deletion gap/libsemigroups/froidure-pin.gd
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Expand Up @@ -13,7 +13,9 @@

DeclareGlobalFunction("LibsemigroupsFroidurePin");

DeclareProperty("CanUseLibsemigroupsFroidurePin", IsSemigroup);
# We increment the rank below so that CanUseLibsemigroupsFroidurePin is used in
# preference to CanUseGapFroidurePin, because o/w they have equal rank.
DeclareProperty("CanUseLibsemigroupsFroidurePin", IsSemigroup, 2);
DeclareOperation("HasLibsemigroupsFroidurePin", [IsSemigroup]);

DeclareOperation("FroidurePinMemFnRec", [IsSemigroup]);
Expand Down
30 changes: 16 additions & 14 deletions gap/libsemigroups/froidure-pin.gi
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Expand Up @@ -244,7 +244,9 @@ end);
InstallMethod(Size, "for a semigroup with CanUseLibsemigroupsFroidurePin",
[IsSemigroup and CanUseLibsemigroupsFroidurePin],
function(S)
if not IsFinite(S) then
if IsFpSemigroup(S) or IsFpMonoid(S) or IsQuotientSemigroup(S) then
TryNextMethod();
elif not IsFinite(S) then
return infinity;
fi;
return FroidurePinMemFnRec(S).size(LibsemigroupsFroidurePin(S));
Expand All @@ -264,7 +266,7 @@ end);
###########################################################################

InstallMethod(AsSet, "for a semigroup with CanUseLibsemigroupsFroidurePin",
[IsSemigroup and CanUseLibsemigroupsFroidurePin],
[CanUseLibsemigroupsFroidurePin and HasGeneratorsOfSemigroup],
function(S)
local result, sorted_at, T, i;
if not IsFinite(S) then
Expand All @@ -288,7 +290,7 @@ end);

InstallMethod(AsListCanonical,
"for a semigroup with CanUseLibsemigroupsFroidurePin",
[IsSemigroup and CanUseLibsemigroupsFroidurePin],
[CanUseLibsemigroupsFroidurePin and HasGeneratorsOfSemigroup],
function(S)
local result, at, T, i;
if not IsFinite(S) then
Expand All @@ -309,7 +311,8 @@ end);

InstallMethod(AsList,
"for a semigroup with CanUseLibsemigroupsFroidurePin",
[IsSemigroup and CanUseLibsemigroupsFroidurePin], AsListCanonical);
[CanUseLibsemigroupsFroidurePin and HasGeneratorsOfSemigroup],
AsListCanonical);

###########################################################################
## Position etc
Expand Down Expand Up @@ -685,7 +688,7 @@ function(S)
or IsQuotientSemigroup(S) then
# Special case required because < for libsemigroups ParialPerms and < for
# GAP partial perms are different.
return AsSet(S);
return Set(AsList(S));
fi;

sorted_at := FroidurePinMemFnRec(S).sorted_at;
Expand Down Expand Up @@ -726,6 +729,7 @@ function(S)

T := LibsemigroupsFroidurePin(S);

# TODO shouldn't S be stored in enum?
enum := rec();

enum.NumberElement := {enum, x} -> PositionCanonical(S, x);
Expand All @@ -739,6 +743,7 @@ function(S)
return EvaluateWord(GeneratorsOfSemigroup(S),
factorisation(T, nr - 1) + 1);
end;
enum.Length := _ -> Size(S);
else
at := FroidurePinMemFnRec(S).at;
enum.ElementNumber := function(enum, nr)
Expand All @@ -748,16 +753,13 @@ function(S)
return at(T, nr - 1);
fi;
end;
fi;

# TODO shouldn't S be stored in enum?
enum.Length := function(_)
if not IsFinite(S) then
return infinity;
else
enum.Length := function(_)
if not IsFinite(S) then
return infinity;
fi;
return Size(S);
fi;
end;
end;
fi;

enum.Membership := {x, enum} -> PositionCanonical(S, x) <> fail;

Expand Down
4 changes: 3 additions & 1 deletion gap/semigroups/semifp.gi
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Expand Up @@ -289,7 +289,9 @@ end);

InstallMethod(ViewObj, "for an f.p. monoid with known generators",
[IsFpMonoid and HasGeneratorsOfMonoid],
4, # to beat the library method
RankFilter(IsSubmonoidFpMonoid and IsWholeFamily and IsMonoid
and HasGeneratorsOfMagma) - RankFilter(IsFpMonoid and HasGeneratorsOfMonoid)
+ 1, # to beat the library method
function(M)
if UserPreference("semigroups", "ViewObj") <> "semigroups-pkg" then
TryNextMethod();
Expand Down
4 changes: 4 additions & 0 deletions gap/semigroups/semiquo.gi
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Expand Up @@ -95,3 +95,7 @@ function(cong)
fi;
return QuotientSemigroupHomomorphism(Q);
end);

InstallMethod(Size, "for a quotient semigroup with known congruence",
[IsQuotientSemigroup and HasQuotientSemigroupCongruence],
Q -> NrEquivalenceClasses(QuotientSemigroupCongruence(Q)));
12 changes: 6 additions & 6 deletions tst/extreme/cong.tst
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Expand Up @@ -137,13 +137,13 @@ gap> v := SemigroupCongruence(s, [gens[1], gens[1]]); # trivial congruence
<2-sided semigroup congruence over <commutative non-regular transformation
semigroup of size 5, degree 10 with 1 generator> with 0 generating pairs>
gap> classes := Set(EquivalenceClasses(v));
[ <2-sided congruence class of Transformation( [ 2, 6, 7, 2, 6, 9, 9, 1, 1,
5 ] )>, <2-sided congruence class of Transformation( [ 6, 9, 9, 6, 9, 1,
1, 2, 2, 6 ] )>, <2-sided congruence class of Transformation( [ 9, 1, 1,
9, 1, 2, 2, 6, 6, 9 ] )>,
<2-sided congruence class of Transformation( [ 1, 2, 2, 1, 2, 6, 6, 9, 9,
[ <2-sided congruence class of Transformation( [ 1, 2, 2, 1, 2, 6, 6, 9, 9,
1 ] )>, <2-sided congruence class of Transformation( [ 2, 6, 6, 2, 6, 9,
9, 1, 1, 2 ] )> ]
9, 1, 1, 2 ] )>, <2-sided congruence class of Transformation( [ 2, 6, 7,
2, 6, 9, 9, 1, 1, 5 ] )>,
<2-sided congruence class of Transformation( [ 6, 9, 9, 6, 9, 1, 1, 2, 2,
6 ] )>, <2-sided congruence class of Transformation( [ 9, 1, 1, 9, 1, 2,
2, 6, 6, 9 ] )> ]
gap> ForAny(EquivalenceClasses(u), x -> x in classes);
false
gap> classes[1] * EquivalenceClasses(u)[1];
Expand Down
6 changes: 3 additions & 3 deletions tst/standard/congruences/cong.tst
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Expand Up @@ -355,7 +355,7 @@ false
gap> class1c < class1a;
true
gap> class1a < class2;
false
true

# IsSuperrelation
gap> S := Semigroup(
Expand Down Expand Up @@ -393,8 +393,8 @@ gap> S := FullTransformationMonoid(3);;
gap> I := SemigroupIdeal(S, Transformation([1, 1, 2]));;
gap> cong := ReesCongruenceOfSemigroupIdeal(I);;
gap> EquivalenceRelationLookup(cong);
[ 1, 2, 3, 11, 5, 6, 11, 8, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
11, 11, 11, 11, 11, 11, 11 ]
[ 1, 2, 3, 4, 5, 6, 4, 8, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4 ]
gap> EquivalenceRelationCanonicalLookup(cong);
[ 1, 2, 3, 4, 5, 6, 4, 7, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4 ]
Expand Down
14 changes: 7 additions & 7 deletions tst/standard/congruences/congpairs.tst
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Expand Up @@ -99,13 +99,13 @@ true
gap> Size(GeneratingPairsOfSemigroupCongruence(v));
0
gap> classes := Set(EquivalenceClasses(v));
[ <2-sided congruence class of Transformation( [ 2, 6, 7, 2, 6, 9, 9, 1, 1,
5 ] )>, <2-sided congruence class of Transformation( [ 6, 9, 9, 6, 9, 1,
1, 2, 2, 6 ] )>, <2-sided congruence class of Transformation( [ 9, 1, 1,
9, 1, 2, 2, 6, 6, 9 ] )>,
<2-sided congruence class of Transformation( [ 1, 2, 2, 1, 2, 6, 6, 9, 9,
[ <2-sided congruence class of Transformation( [ 1, 2, 2, 1, 2, 6, 6, 9, 9,
1 ] )>, <2-sided congruence class of Transformation( [ 2, 6, 6, 2, 6, 9,
9, 1, 1, 2 ] )> ]
9, 1, 1, 2 ] )>, <2-sided congruence class of Transformation( [ 2, 6, 7,
2, 6, 9, 9, 1, 1, 5 ] )>,
<2-sided congruence class of Transformation( [ 6, 9, 9, 6, 9, 1, 1, 2, 2,
6 ] )>, <2-sided congruence class of Transformation( [ 9, 1, 1, 9, 1, 2,
2, 6, 6, 9 ] )> ]
gap> EquivalenceClasses(u)[1] in classes;
false
gap> classes[1] * EquivalenceClasses(u)[1];
Expand All @@ -128,7 +128,7 @@ true
gap> classes[2] = classes[3];
false
gap> AsList(classes[4]);
[ Transformation( [ 1, 2, 2, 1, 2, 6, 6, 9, 9, 1 ] ) ]
[ Transformation( [ 6, 9, 9, 6, 9, 1, 1, 2, 2, 6 ] ) ]
gap> Size(classes[4]);
1

Expand Down
4 changes: 2 additions & 2 deletions tst/standard/congruences/congrees.tst
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Expand Up @@ -261,8 +261,8 @@ gap> cong := ReesCongruenceOfSemigroupIdeal(I);
<Rees congruence of <regular transformation semigroup ideal of degree 3 with
1 generator> over <full transformation monoid of degree 3>>
gap> EquivalenceRelationLookup(cong);
[ 1, 2, 3, 11, 5, 6, 11, 8, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
11, 11, 11, 11, 11, 11, 11 ]
[ 1, 2, 3, 4, 5, 6, 4, 8, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4 ]
gap> EquivalenceRelationCanonicalLookup(cong);
[ 1, 2, 3, 4, 5, 6, 4, 7, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
4, 4 ]
Expand Down
8 changes: 4 additions & 4 deletions tst/standard/libsemigroups/cong.tst
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Expand Up @@ -194,9 +194,9 @@ gap> C := LeftSemigroupCongruence(S, [[S.1, S.1 ^ 10]]);
<left semigroup congruence over <free band on the generators [ x1, x2 ]> with
0 generating pairs>
gap> AsSSortedList(EquivalenceClasses(C));
[ <left congruence class of x1>, <left congruence class of x2x1>,
<left congruence class of x1x2x1>, <left congruence class of x2>,
<left congruence class of x1x2>, <left congruence class of x2x1x2> ]
[ <left congruence class of x1>, <left congruence class of x2x1x2>,
<left congruence class of x2x1>, <left congruence class of x2>,
<left congruence class of x1x2>, <left congruence class of x1x2x1> ]
gap> D := LeftSemigroupCongruence(S, [[S.1, S.2 ^ 10]]);
<left semigroup congruence over <free band on the generators [ x1, x2 ]> with
1 generating pairs>
Expand All @@ -218,7 +218,7 @@ gap> u := Image(hom, Transformation([1, 1, 1, 1]));
gap> t := Image(hom, Transformation([2, 1, 2, 3]));
<2-sided congruence class of Transformation( [ 2, 1, 2, 3 ] )>
gap> t < u;
true
false

# EquivalenceClasses for a congruence with infinitely many classes
gap> S := FreeSemigroup(2);
Expand Down
46 changes: 23 additions & 23 deletions tst/standard/semigroups/semiquo.tst
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Expand Up @@ -176,14 +176,14 @@ gap> IrredundantGeneratingSubset(S / cong);
[20,17][29,32][30,31](1,4)(2,3)(5,8)(6,7)> ]
gap> SmallSemigroupGeneratingSet(S / cong);
[ <2-sided congruence class of <identity partial perm on [ 1, 2, 3, 4 ]>>,
<2-sided congruence class of (1,3)(2,4)(21,23)(22,24)(25,27)(26,28)(33,35)
(34,36)>, <2-sided congruence class of (1,2)(3,4)(5,6)(7,8)(11,12)(13,14)
(19,20)(29,30)> ]
<2-sided congruence class of (1,2)(3,4)(5,6)(7,8)(11,12)(13,14)(19,20)
(29,30)>, <2-sided congruence class of (1,3)(2,4)(21,23)(22,24)(25,27)
(26,28)(33,35)(34,36)> ]
gap> GeneratorsSmallest(S / cong);
[ <2-sided congruence class of <identity partial perm on [ 1, 2, 3, 4 ]>>,
<2-sided congruence class of (1,2)(3,4)(5,6)(7,8)(11,12)(13,14)(19,20)
(29,30)>, <2-sided congruence class of [11,10][12,9][13,16][14,15][19,18]
[20,17][29,32][30,31](1,4)(2,3)(5,8)(6,7)> ]
(29,30)>, <2-sided congruence class of (1,3)(2,4)(21,23)(22,24)(25,27)
(26,28)(33,35)(34,36)> ]

# Issue 816 - Subsemigroups of quotient semigroups
gap> S := Semigroup(Transformation([2, 1, 5, 1, 5]),
Expand Down Expand Up @@ -211,8 +211,8 @@ true
gap> Factorization(H, images[2]);
[ 2 ]
gap> map := IsomorphismFpSemigroup(T);
<quotient of <2-sided semigroup congruence over <transformation semigroup of
degree 5 with 3 generators> with 1 generating pairs>> ->
<quotient of <2-sided semigroup congruence over <transformation semigroup
of size 59, degree 5 with 3 generators> with 1 generating pairs>> ->
<fp semigroup with 3 generators and 8 relations of length 33>
gap> map := IsomorphismFpSemigroup(Q);
<semigroup of size 4, with 3 generators> ->
Expand All @@ -234,42 +234,42 @@ gap> Q := S / cong;
degree 5 with 3 generators> with 1 generating pairs>>
gap> CongruencesOfSemigroup(Q);
[ <2-sided semigroup congruence over <quotient of <2-sided semigroup congruenc\
e over <transformation semigroup of degree 5 with 3 generators> with
e over <transformation semigroup of size 59, degree 5 with 3 generators> with
1 generating pairs>> with 0 generating pairs>,
<universal semigroup congruence over <quotient of <2-sided semigroup congrue\
nce over <transformation semigroup of degree 5 with 3 generators> with
1 generating pairs>>>,
nce over <transformation semigroup of size 59, degree 5 with 3 generators>
with 1 generating pairs>>>,
<2-sided semigroup congruence over <quotient of <2-sided semigroup congruenc\
e over <transformation semigroup of degree 5 with 3 generators> with
e over <transformation semigroup of size 59, degree 5 with 3 generators> with
1 generating pairs>> with 1 generating pairs>,
<2-sided semigroup congruence over <quotient of <2-sided semigroup congruenc\
e over <transformation semigroup of degree 5 with 3 generators> with
e over <transformation semigroup of size 59, degree 5 with 3 generators> with
1 generating pairs>> with 1 generating pairs>,
<2-sided semigroup congruence over <quotient of <2-sided semigroup congruenc\
e over <transformation semigroup of degree 5 with 3 generators> with
e over <transformation semigroup of size 59, degree 5 with 3 generators> with
1 generating pairs>> with 1 generating pairs>,
<2-sided semigroup congruence over <quotient of <2-sided semigroup congruenc\
e over <transformation semigroup of degree 5 with 3 generators> with
e over <transformation semigroup of size 59, degree 5 with 3 generators> with
1 generating pairs>> with 1 generating pairs> ]
gap> map := QuotientSemigroupHomomorphism(Q);
<transformation semigroup of degree 5 with 3 generators> ->
<quotient of <2-sided semigroup congruence over <transformation semigroup of
degree 5 with 3 generators> with 1 generating pairs>>
<transformation semigroup of size 59, degree 5 with 3 generators> ->
<quotient of <2-sided semigroup congruence over <transformation semigroup
of size 59, degree 5 with 3 generators> with 1 generating pairs>>
gap> Q := Q / SemigroupCongruence(Q,
> [[Transformation([2, 1, 5, 1, 5]) ^ map,
> Transformation([2, 5, 3, 5, 3]) ^ map]]);
<quotient of <2-sided semigroup congruence over <quotient of <2-sided semigrou\
p congruence over <transformation semigroup of degree 5 with 3 generators>
with 1 generating pairs>> with 1 generating pairs>>
p congruence over <transformation semigroup of size 59, degree 5 with 3
generators> with 1 generating pairs>> with 1 generating pairs>>
gap> CongruencesOfSemigroup(Q);
[ <2-sided semigroup congruence over <quotient of <2-sided semigroup congruenc\
e over <quotient of <2-sided semigroup congruence over <transformation
semigroup of degree 5 with 3 generators> with 1 generating pairs>> with
1 generating pairs>> with 0 generating pairs>,
semigroup of size 59, degree 5 with 3 generators> with
1 generating pairs>> with 1 generating pairs>> with 0 generating pairs>,
<universal semigroup congruence over <quotient of <2-sided semigroup congrue\
nce over <quotient of <2-sided semigroup congruence over <transformation
semigroup of degree 5 with 3 generators> with 1 generating pairs>> with
1 generating pairs>>> ]
semigroup of size 59, degree 5 with 3 generators> with
1 generating pairs>> with 1 generating pairs>>> ]
gap> Size(Q);
2

Expand Down
2 changes: 1 addition & 1 deletion tst/testinstall.tst
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Expand Up @@ -910,7 +910,7 @@ gap> x := ReesZeroMatrixSemigroupElement(R, 1, (1, 3), 1);;
gap> y := ReesZeroMatrixSemigroupElement(R, 1, (), 1);;
gap> cong := SemigroupCongruenceByGeneratingPairs(R, [[x, y]]);;
gap> c := Set(EquivalenceClasses(cong));
[ <2-sided congruence class of (1,(),1)>, <2-sided congruence class of 0>,
[ <2-sided congruence class of 0>, <2-sided congruence class of (1,(),1)>,
<2-sided congruence class of (1,(),2)>,
<2-sided congruence class of (1,(),3)>,
<2-sided congruence class of (1,(),4)>,
Expand Down
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