PermBounds( tbl, d )
All characters pi satisfying pi(g) > 0 and pi(1) = d for a given
degree d lie in a simplex described by these conditions. PermBounds
computes the boundary points of this simplex for d = 0, from which the
boundary points for any other d are easily derived. Some conditions
from the powermap are also involved.
For this purpose a matrix similar to the rationalized character table has to be inverted.
These boundary points are used by PermChars (see PermChars) to
construct all permutation character candidates of a given degree.
PermChars either calls PermBounds or takes this information from the
record field bounds of its argument record.
GAP 3.4.4