guile-examples/modules/r6rs-libraries/helper.scm

;; The import-spec contains all parts from the root of the project to the
;; module.
(library (helper)
  (export myproc)

  ;; To be able to use the ~library~ form, you need to import (rnrs base).
  (import (except (rnrs base) let-values map error)
          ;; Importing only λ from guile for this module.
          (only (guile) λ))

  (define myproc
    (λ (arg)
      (+ arg 2))))