gistfile1.scm

(define-library (scheme linear-algebra)
  (import (rename (scheme base) (* r7rs:*)))
  (export *)
  (begin
    (define (* x y)
      (if (or (array? x) (array? y))
        (array-multiplication x y)
        (r7rs:* x y)))

    (define (array? obj) ...)

    (define (array-multiplication x y) ...)
    ))