A relational symbol indicating that two quantities can be either greater than or less than each other.
Examples
Comparing two variables that may vary in relation to each other
x \gtrless y \text{ depending on the value of } t
Economic relationship between supply and demand
P_1 \gtrless P_2 \text{ when market conditions fluctuate}
Comparing expressions with unknown values
a + b \gtrless c - d \text{ for arbitrary real numbers}