CollapsedMat( mat, maps )
returns a record with fields mat
and fusion
: The fusion
field
contains the fusion that collapses the columns of mat that are
identical also for all maps in the list maps, the mat
field contains
the image of mat under that fusion.
gap> t.irreducibles; [ [ 1, 1, 1, 1, 1 ], [ 3, -1, 0, -E(5)-E(5)^4, -E(5)^2-E(5)^3 ], [ 3, -1, 0, -E(5)^2-E(5)^3, -E(5)-E(5)^4 ], [ 4, 0, 1, -1, -1 ], [ 5, 1, -1, 0, 0 ] ] gap> t:= CharTable( "A5" );; RationalizedMat( t.irreducibles ); [ [ 1, 1, 1, 1, 1 ], [ 6, -2, 0, 1, 1 ], [ 4, 0, 1, -1, -1 ], [ 5, 1, -1, 0, 0 ] ] gap> CollapsedMat( last, [] ); rec( mat := [ [ 1, 1, 1, 1 ], [ 6, -2, 0, 1 ], [ 4, 0, 1, -1 ], [ 5, 1, -1, 0 ] ], fusion := [ 1, 2, 3, 4, 4 ] ) gap> Restricted( last.mat, last.fusion ); [ [ 1, 1, 1, 1, 1 ], [ 6, -2, 0, 1, 1 ], [ 4, 0, 1, -1, -1 ], [ 5, 1, -1, 0, 0 ] ]
GAP 3.4.4