CIGAL recognizes hundreds of different words as either data variables
or commands. Some variables and commands are internally defined, others
are user-defined.

The program looks for the meaning of each word entered in a command line by a 4-step process checking:
1) the list of DEFINE'd names
2) the list of internally declared variables
3) the list of user-declared variables
4) the list of internally defined commands and functions. In the first 3 of these steps only exact matches are accepted, but CIGAL will recognize any unambiguous abbreviations (of 2 or more letters) for command or function names.

The following is a list of CIGAL's internally defined words organized by command or variable type. The names in this list should normally be treated as reserved words and therefore should not be used as names for variables or macro programs. (It is possible, however, to change the meaning of any reserved word by using the DEFINE command.) These names are listed in alphabetical order.

accept acos adjust aflags alarm
align alog analyze angle arc
area array asin axis barleng
bin bitmask block box break
byte calbar call camera cgain
circle close cmdlin coffset compile
compress convolve copy core correlate
cos cpuspeed ctrap cursor cursval
cursx cursy cylinder dac0 dac1
datadir debug declare default define
delete digitize directory edit editor
ellipse else erase errors execute
file fill filter findvec flags
flip fmenu format freestack freeze
frequency ftype getchar getvec getx
getxy gety getz gflags global
goto gplane hdrtxt help helpfile
histogram ibase idiv if iflags
image initialize input integer invert
ipalu iplane ipwait journal keybd
label lastvec lcase lcolor length
line link list log long
lpat lwidth macro maklut manual
map margin margsize mask matmul
matrix max mean measure menu
menuflag min mode nargs next
number nvecs obase offset open
outlun output overlay paint path
peak penwidth pin plot pointer
portio prepro printer prompt prpage
putvec quit quitstr ramp random
read real redraw release rem
return roam rotate round run
sample scale search sflags shift
show sin size sketch smooth
solid sort spawn sphere sqrt
stack state stats stdev stretch
string substitute sum sysdir sysint
tablet terminal text tile time
track type ucase unit user1
user2 user3 vecfile vecs vector
version view vimage vmode vplane
vwidth wait warp while write
xmarg xor zimage zmap zoom
zvalue

! != & &= (
) * ** **= *=
+ ++ += - --
-= / // //= /=
< <= = == >
>= >> >>= [ ]
{ | |= } ]