### 3.2 SCM Primitive Procedures

Real-only versions of transcedental procedures (warning: these
procedures are not compiled directly into the corresponding C library
procedures, but a combination of internal SCM procedures, guaranteeing exact
correspondence with the SCM interpreter while hindering the speed):

real-sqrt real-exp real-ln real-expt real-sin real-cos real-tan
real-asin real-acos real-atan real-sinh real-cosh real-tanh real-asinh
real-acosh real-atanh

*Note Bene:* These procedures are compiled to faster code than the
corresponding generic versions `sqrt`, `abs`, ... `expt`.

A selection of other extra primitives in SCM is also recognized as
primitives. eg. `get-internal-run-time`, `quit`, `abort`,
`restart`, `chdir`, `delete-file`, `rename-file`.