George McNinch wrote:
GAP4, Version: 4r2 of 29-Feb-2000, i686-pc-linux-gnu-gcc gap> R := Integers mod 9; (Integers mod 9) gap> S := FullMatrixAlgebra(R,2); ( (Integers mod 9)^[ 2, 2 ] ) gap> Units(S); Segmentation fault
A crash certainly is a bug. As noted already, this bug has been corrected
in one of the bugfixes for GAP4R2.
However (as also noted) now GAP 4.2 will stop with an error message (``No
method found'') that indicates that the capability to test invertibility of a
matrix in this ring has not been implemented.
(The forthcoming release 4.3 will be able to calculate the units in this
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