atlas Library · Script File
exceptional.at
Tables of Weyl group conjugacy classes and Nilpotent Orbits for the exceptional groups
Definitions in source order
EllipticDatum type
set_type EllipticDatum = (WeylElt w,[int] charpoly, int order, int length, string name, int size)
Fields: w, charpoly, order, length, name, size
data type for table of elliptic conjugacy classes could be expanded to all conjugacy classes
EllipticTable type
set_type EllipticTable=[EllipticDatum]
root_datum
root_datum(EllipticTable T)table is assumed non-empty and all WeylElt are for same RootDatum
also in this file at line 63; also defined in basic.at, W_reps.at, K_Nilpotent.at, sommers.at, parabolics.at, K.at, nilpotent_orbits.at, W_classes.at, extended_misc.at, character_tables.at, springer_tables.at, disconnected.at, cyclotomic_Lie_algebra.at, bracket.at
lookup_by_name
lookup_by_name(EllipticTable T,string name) = intalso in this file at line 64
show
show(EllipticTable T) = voidnice output of table
also in this file at line 75; also defined in modules.at, K_Nilpotent.at, good_W_representatives.at, arthur_parameters.at, sub_cells.at, associated_variety_annihilator.at, geck_generic.at, L_packet.at, ratmat.at, Levi_subgroups.at, nilpotent_orbits.at, subgroups.at, poset.at, cyclotomic.at, polynomial.at, character_tables.at, springer_tables.at, hodgeParamLaurentPol.at, hodgeParamPol.at, laurentPolynomial.at, weak_packets.at, cyclotomic_Lie_algebra.at, cyclotomicMat.at, bracket.at, nilpotent_posets.at, lazy_lists.at
show_long
show_long(EllipticTable T) = voidinclude a representative of each class
also defined in character_tables.at, springer_tables.at, hodgeParamLaurentPol.at, hodgeParamPol.at, weak_packets.at, cyclotomic_Lie_algebra.at, bracket.at
NilpotentDatum type
set_type NilpotentDatum=(RootDatum root_datum,string name ,string alt_name,int special,[int] closure,string dual,string A,string Abar,[int] diagram)
Fields: root_datum, name, alt_name, special, closure, dual, A, Abar, diagram
data type for a table of information about nilpotent orbits
name: according to Carter alt_name: Spaltenstein/Mizuno etc., when different special: 1 or 0 closure: orbits in the closure (not including itself) dual: name of dual orbit A: string giving A(O) Abar: Lusztig's quotient diagram: labeled Dynkin diagram
orbit
orbit(NilpotentDatum d) = ComplexNilpotentalso defined in springer_tables.at, W_reps_type_BC.at
dimension
dimension(NilpotentDatum d) = intalso defined in basic.at, finite_dimensional.at, K_highest_weights.at, nilpotent_orbits.at, character_tables.at, W_reps_type_BC.at, tensor_product.at
is_special
is_special(NilpotentDatum d) = boolalso defined in combinatorics.at, springer_tables.at, W_reps_type_BC.at
is_even
is_even(NilpotentDatum d) = boolalso defined in basic.at, nilpotent_orbits.at
H
H(NilpotentDatum d)_of_triple
also defined in groups.at, cyclotomic_Lie_algebra.at, bracket.at
Levi
Levi(NilpotentDatum d) = RootDatumalso defined in parabolics.at
is_distinguished
is_distinguished(NilpotentDatum d) = boolalso defined in sommers.at, twisted_root_datum.at
NilpotentTable type
set_type NilpotentTable=[NilpotentDatum]
root_datum
root_datum(NilpotentTable T) = RootDatumalso in this file at line 16; also defined in basic.at, W_reps.at, K_Nilpotent.at, sommers.at, parabolics.at, K.at, nilpotent_orbits.at, W_classes.at, extended_misc.at, character_tables.at, springer_tables.at, disconnected.at, cyclotomic_Lie_algebra.at, bracket.at
lookup_by_name
lookup_by_name(NilpotentTable T,string name) = intalso in this file at line 18
lookup_by_alt_name
lookup_by_alt_name(NilpotentTable T,string alt_name) = intlookup_by_diagram
lookup_by_diagram(NilpotentTable T,[int] diagram) = intlong_name 2 overloads
long_name(NilpotentDatum row) = stringlong_name(NilpotentTable T,int i) = stringshow
show(NilpotentTable T) = voidnice output
also in this file at line 22; also defined in modules.at, K_Nilpotent.at, good_W_representatives.at, arthur_parameters.at, sub_cells.at, associated_variety_annihilator.at, geck_generic.at, L_packet.at, ratmat.at, Levi_subgroups.at, nilpotent_orbits.at, subgroups.at, poset.at, cyclotomic.at, polynomial.at, character_tables.at, springer_tables.at, hodgeParamLaurentPol.at, hodgeParamPol.at, laurentPolynomial.at, weak_packets.at, cyclotomic_Lie_algebra.at, cyclotomicMat.at, bracket.at, nilpotent_posets.at, lazy_lists.at
nilpotent_poset
nilpotent_poset(NilpotentTable T) = NilpotentPosetextract NilpotentPoset from the table
also defined in nilpotent_posets.at
closure
closure(NilpotentTable T) = NilpotentTablefill in all orbits in the closure of each given one (not just covering relations)
also defined in K_Nilpotent.at, poset.at
sub_table 2 overloads
sub_table(NilpotentTable T, [int] S) = NilpotentTableextract table given by rows the closure relations require work (throwing out terms and renumbering)
sub_table(NilpotentTable T,(NilpotentDatum->bool) selection_function) = NilpotentTablealso defined in structure_constants.at
text_save
text_save(NilpotentTable T,string name)save a table in a form that can be read in by atlas
shift_closures_by_one
shift_closures_by_one(NilpotentTable T) = NilpotentTabletool for fixing the closures, the source files numbered starting at 1 not 0, this shouldn't be needed any more
graph
graph(NilpotentTable T,[string] labels) = stringgraph from a table, with specified labels
also in this file at line 159, line 167; also defined in poset.at, nilpotent_posets.at
preimage
preimage([(string ,string)] pairs,string y) = stringgiven function from strings -> strings, find preimage
lusztig_graph
lusztig_graph(NilpotentTable T,[(string,string)] lusztig_map)graph showing closure relations in the image of Lusztig's map from [W] to N, restricted to elliptic elements
graph 2 overloads
graph(NilpotentPoset P,NilpotentTable T) = stringgraph of a nilpotent poset (see nilpotent_posets.at), using the table for the names
graph(NilpotentTable T) = stringalso in this file at line 127; also defined in poset.at, nilpotent_posets.at
extract sub_table by rule on row, see is_special etc. just after set_type NilpotentDatumL170
sub_table_distinguished
sub_table_distinguished(NilpotentTable T) = NilpotentTablesub_table_even
sub_table_even(NilpotentTable T) = NilpotentTableGenerated from atlas-scripts at commit 648506c (2026-10-13).
Commented-out code, lines 129–136 (5 lines)
{graph from a table, with labels integer, name and alt_name (when different) } set graph(NilpotentTable T)=string: graph(T, for i:#T do i.to_string + " " + T[i].name + ":" + T[i].alt_name od )