In 2008/2009 there was a Single Interval Mathematics Package (SIMP) for Octave, which has eventually become unmaintained at Octave Forge.
The simp package contains a few
, simple arithmetic operations on scalar intervals. It does not consider inaccurate built-in arithmetic functions, round-off, conversion and representational errors. As a result its syntax is very easy, but the arithmetic fails to produce guaranteed enclosures.
It is recommended to use the interval package as a replacement for simp. However, function names and interval constructors are not compatible between the packages.