Turtle-> new turtle menu.
A logo level is made of three parts, the graphic display
in the middle, a subsession of commandlines at the left
and an editor at the right. Commandlines are executed as in
a main session (commandlines below an evaluated command
are not reevaluated unlike in a geometry session). The editor
records all commands.
In a logo level, you can pilot a turtle, giving it orders like forward
10 steps, turn left or right, etc. It will display a trace
using a pen with a defined color.
You can use any language construction of Xcas to program the
turtle moves. The current language use French commandnames
(e.g. avance=move forward, etc.), the most important commandnames
are available by clicking on the buttonbar below the turtle screen
(check that the cursor is on a commandline before clicking on
the button corresponding to the command you want to enter).
Most commands have a default argument (e.g. 10 for avance),
if you want to add parameters, do not add parenthesis. Logo
commands use the same syntax as the return statement,
if you want to specify priorities, put parenthesis around
the command and arguments, like this (hasard 10).