Tyl has prebuilt variables that have a fixed value during program run.
Tyl system variables features:
Throughout this guide all system variables in code boxes are in dark blue color.

Say we want to print a new line in a text file. We can use newline system variable for it:
print 'first line' + newline + 'second line'
first line
second line
System variables are used as regular variables, they can be assigned to another variables:
nl newline
t tab
mulsym unicode '2022'
rad 10
pi math.pi
print 'The perimeter of a circle with' + nl + 'radius 10, is:' + nl + nl + t + '2 ' + mulsym + ' π ' + mulsym + ' R = ' + calcperim rad
calcperim r: 2 pi r
The perimeter of a circle with
radius 10, is:

 2 • π • R = 62.8318530717958
nl variable was assigned the value of newline system variable. tab and math.pi are also system variables, that were assigned to variables with shortened names. unicode is a system function that is used to get a UNICODE character.

All system variables are in System Variables Reference