Constructor for matrices. The arguments are a list of rows in the matrix.
(Undefined (Arity Matrix-Of-Rows)) (<=> (= (Matrix-Of-Rows @Elements) ?M) (And (Matrix ?M) (= (Row-Dimension ?M) (Length (Listof @Elements))) (= (Row ?I ?M) (Nth (Listof @Elements) ?I)) (=> (And (Item ?E1 (Listof @Elements)) (Item ?E2 (Listof @Elements))) (= (Column-Dimension ?E1) (Column-Dimension ?E2)))))