better implementation of zero-matrix
better implementation of zero-matrix

littledan/Factor,mcandre/factor,mcandre/factor,erg/factor,erg/factor,cataska/factor,erg/factor,erg/factor,ceninan/factor,littledan/Factor,erg/factor,mcandre/factor,cataska/factor,littledan/Factor,ceninan/factor,kingcons/factor,mcandre/factor,kingcons/factor,seckar/factor,seckar/factor,kingcons/factor,mcandre/factor,ceninan/factor,cataska/factor,mcandre/factor,erg/factor,erg/factor,ceninan/factor,kingcons/factor,seckar/factor,littledan/Factor,cataska/factor,mcandre/factor