CheckHeckeDefiningRelations( H , t )
  
returns true or false, according  to whether a  given set t of matrices
corresponding to the standard generators  of the Coxeter group Group(H)
defines a representation of the Iwahori-Hecke algebra H or not.
    gap> H := Hecke(CoxeterGroup( "F", 4 ));;
    gap> r := HeckeReflectionRepresentation( H );;
    gap> CheckHeckeDefiningRelations( H, r );
    true 
This function requires the package "chevie" (see RequirePackage).
GAP 3.4.4