• || ... is a pattern object which represents any of the patterns .
Notes
• 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_].
Usage
. 
, you cannot use these pattern names on the right-hand side of transformation rules for the pattern. Thus, for example, you can use 
