Combining Annuity Symbol

It is an actuarial modifier; the whole formula gives its reading.

An annuity is a series of payments. In actuarial notation, the combining annuity symbol sits with a main symbol, and position carries meaning: lower left can mark duration or timing, lower right age or event order, and upper right payment frequency. A letter or number enclosed by a right angle denotes a fixed number of years.

Actuarial notation predates computers. It grew from a key in George King's life-contingencies textbook (a guide to payments tied to a person's lifetime); an international congress adopted an explanatory statement in London in 1898. Dr. Sprague rearranged the symbols in 1900 while leaving nearly all unchanged. A revision planned for 1940 was delayed by war and appeared in a 1950 account.

Why is ⃧ misaligned?

It needs a base character and font support.

As a nonspacing mark, ⃧ has no advance width; layout positions it relative to the preceding character. When it is unattached, a dotted circle may stand in for its missing base. The circle is a display aid, not part of the mark.

A font without the mark may show a missing-glyph box; supported fonts can draw the angle differently. Text and appearance are separate: the encoded character stays the same even when its placement looks wrong.

How do I type ⃧?

Use Unicode input, or let an actuarial LaTeX package build the notation.

As of 2026-09-06, Julia's Unicode input table lists \annuity for this mark, and unicode-math provides the same macro. In code, enter \u20E7 where that escape is supported, or choose the mark in a Unicode picker.

A dedicated actuarial LaTeX package can align a full formula's subscripts and superscripts; the combining mark alone does not arrange them.