Circled Minus

The circled minus marks symmetric difference between two sets. A set is a collection of items: A ⊖ B keeps each item found in A or B, but not both. That is the same yes-or-no rule as exclusive OR (XOR).

This is a defined operation, not a decorative version of ordinary subtraction.

Why can ⊖ mean something else?

Different technical conventions assign it different jobs. In an ISO 2047 keyboard-symbol convention, ⊖ denotes Escape; in set notation, it marks symmetric difference. The nearby formula or label tells you which convention is in play.

In chemistry, the standard-state superscript is the related Plimsoll mark ⦵; do not assume it is ⊖. Unicode's 1993 encoding date tells when this character entered Unicode, not when the notation began.

A mathematical operator repertoire lists ⊖ with circled plus ⊕, circled times ⊗, and boxed minus ⊟. Their shared design marks a family; it does not make the operations interchangeable.

Why does circled minus look split?

Some fonts draw a bar that seems to cut the circle. As of 2026, some fonts show ⊖ with its horizontal stroke bisecting the rim. That is a difference in drawing, not a different character.

The sequence ⊖︀ adds a variation selector. Fonts that support it may draw the circle more distinctly, but the selector does not guarantee a particular appearance.