Texas Instruments TI-80 L (Negation)

2-6 Math, Angle, and Test Operations
L (negation, ·) returns the negative of a number, expression,
or list. The narrow negation symbol (L) distinguishes negation
from the subtraction or minus (–).
Lvalue
EOS rules (Chapter 1) determine when negation is evaluated.
For example, LA2 returns a negative number because squaring
is evaluated before negation. Use parentheses to square a
negated number, (LA)2.
ABS (absolute value, 2 P) returns the absolute value of a
number, expression, or list.
ABS value
Pi (2 T) is stored as a constant in the TI-80. Press 2 T
to copy the symbol p to the cursor location. The number
3.141592654 is displayed for p, but 3.1415926535898 is used
internally in calculations.
L (Negation)
ABS
p (Pi)