*! version 1.0.0 Fri Apr 23 13:19:04 PDT 1993
program define mateq /* m1 m2 tolerance */
	version 3.1
	local m1 "`1'"
	local m2 "`2'"
	local tol=`3'
	tempname dif sc
	mat `dif' = `m1' - `m2' 
	mat `dif' = `dif' ' * `dif'
	scalar `sc' = trace(`dif')
	capture assert `sc'<=`tol'
	if _rc { 
		di in red "assertion is false; observed sq. dif. " `sc'
		assert 1==2
	}
	di "(" `sc' ")"
end