A comment start with a ‘#’ and finish with an end of line::
% # this is a comment


A variable is defined by the keyword ‘let’ and its name always start with a $.

There is two kind of variables: Toplevel variables —————— toplevel variables: they are directly declared without beiing within a function. For exemple:

  % let $topv = 5

We here have a toplevel variable usable everywhere in the code by calling it::
  % topv

Scoped variables

A scoped variable is limited to a given perimeters.::
% let $scopedv = 5 in ($scopedv + 4) 9

The variable only exist in the in (…) code and is not reachable elsewhere.

In a function only scoped variables can be used.


Condition can be expressed like this::
% if (boolean_expr) then (value_when_true) else (value_when_false)

Instructions sequence

You can do instruction sequence using “;;”::
% (instr1) ;; (instr2)

Take care that in this case, instr1 will be only usefull for its side-effects.