 
| X | Is the element type of the Monoid. | 
| a, b | are objects of type X. | 
| op | Is the function object implementing the Monoid operation. | 
| i | is an object of type X and is the identity element for the Monoid. | 
| op(a, b) | See below for semantics. Return type: X | 
| a == b | Returns true if a and b represent
     the same element of S. Return type: bool | 
| a != b | Returns true if a and b represent
     different elements of S. Return type: bool | 
| Copyright © 2000-2001 | Jeremy Siek,
Indiana University (jsiek@osl.iu.edu) Lie-Quan Lee, Indiana University (llee@cs.indiana.edu) Andrew Lumsdaine, Indiana University (lums@osl.iu.edu) |