## Definitions

### from The Century Dictionary.

• noun In chem., combining capacity, according as an element or a compound is a monad, dyad, etc.; same as valency.

• noun logic, mathematics, computer science The number of arguments or operands a function or operation takes. For a relation, the number of domains in the corresponding Cartesian product.
• noun chemistry, obsolete Valence.

## Etymologies

From Ancient Greek root -ad, + -icity. Compare arity, which comes from the corresponding Latin root.

## Examples

• Peirce's so-called “Reduction Thesis” is the thesis that all relations, relations of arbitrary adicity, may be constructed from triadic relations alone, whereas monadic and dyadic relations alone are not sufficient to allow the construction of even a single

• Again: rheme (by which Peirce meant a relation of arbitrary adicity or arity) was a first, proposition was a second, and argument was a third.

• In 1870 Peirce published a long paper “Description of a Notation for the Logic of Relatives” in which he introduced for the first time in history, two years before Frege's Begriffschrift a complete syntax for the logic of relations of arbitrary adicity (or: arity).

• An account of the number and role of the relata should first formulate general determinants of the adicity of relations, and then apply these determinants to causation.

The Metaphysics of Causation Schaffer, Jonathan 2007

• Contrastivity Revisited: A final argument to consider on the question of selection revisits adicity

The Metaphysics of Causation Schaffer, Jonathan 2007

• As to number and role, the dispute presupposes that there is a unique number that is the adicity.

The Metaphysics of Causation Schaffer, Jonathan 2007

• Two points remain to be mentioned: The first is the relationship between alteration of adicity and two series (ous and ic) of compounds.

• NH_ {3}, NH_ {4} Cl. The term "capacity of saturation," may be used as a synonym for adicity, if care be taken to distinguish it from other kinds of saturation, such as an acid with an alkali, etc.

• The lecturer then referred to an important difference in the adicity of chlorine and oxygen.

• He next considered the possibility of assigning a fixed limit to this valency or adicity of an atom, and concluded that the adicity was not absolutely fixed, but was fixed in relation to certain elements, e.g.,