What is "triple bar"

n. The symbol ≡, consisting of three parallel horizontal lines.

The triple bar, ≡, is a symbol with multiple, context-dependent meanings. It has the appearance of a " =" sign with a third line. The triple bar character in Unicode is codepoint . The closely related codepoint is the same symbol with a slash through it, indicating the negation of its mathematical meaning. In LaTeX mathematical formulas, the code \equiv produces the triple bar symbol as output.