Alternatives

| | ... is a pattern object which represents any of the patterns .

Example: _Integer | _Real represents an object with head either Integer or Real.

Unless the same set of pattern names appears in all of the , you cannot use these pattern names on the right-hand side of transformation rules for the pattern. Thus, for example, you can use x in a[x_] | b[x_], but you can use neither x nor y in a[x_] | b[y_].

See The Mathematica Book: Section 2.3.6.

See also: Optional.

Further Examples