10.2: Online Help

Type `help' followed by a command-name: assert cd close convert create debug delete differentiate draw expecting filter flip get help if ignore input insert interpolate list ls mask move new open pwd query quit read regress reorder rescale resize return rewind set show skip sleep smooth source sprintf state superuser system write Or type `help -' followed by a topic from this list: example extending files math strings synonyms variables manual

Some commands have more words than shown. You can type these additional words to narrow the help down; otherwise Gri will give you help on all commands that begin with the indicated words. For example, try `help set' and `help set x'. When you ask for help on a multi-word command, Gri tells you about all commands which begin with the words you've typed. Thus,

help help draw help draw zero help draw zero line

narrow in on the command `draw zero line'. The response to the most complete request is

`draw zero line [horizontally|vertically]' draw zero line Draw line y=0 if it is within axes draw zero line horizontally Draw line y=0 if it is within axes draw zero line vertically Draw line x=0 if it is within axes

The part enclosed in angled quotes is the syntactical description of the command. (NOTE: The square brackets indicate an optional word (in this case) or words. The vertical bar indicates that either the item on the left or the item on the right may appear; it is a logical OR operator. The only other special characters in syntax descriptions are the braces `{}', which are used to enclose multiple words which act as one unit; they are used to clarify the choices presented to the OR operator.) Following the syntactical description are examples. Each example is indented 2 spaces, and a description of it (which always starts with an upper-case character and ends with a period, to indicate that it is an English description) follows that, indented by an additional 2 spaces.