Tyl has pre-built variables that can be used by the programmer in Tyl code.
Tyl system variables features:
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 a regular variables, they can be assigned to another variable:
nl newline
t tab
rad 10
pi math.pi
print 'The perimeter of a circle with' + nl + 'radius: 10, is:' + nl + nl + t + '2 * π * R = ' + 2 * pi * rad
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 name.

All system variables are in System Variables Reference