input iterator requirements in Table 72 in the Standard document

[subramanian100in]

In the ISO/IEC 14882:2003 document, in section '24.1.1 Input
Iterators' in page 517, in Table 72, I need some clarifications/
explanations.

For the operation 'a == b', the 'semantics, pre/post conditions'
column says:
'== is an equivalence relation over its domain'
Where can I find the definition of 'equivalence relation' in the
standard document ? If it is not defined in this document, kindly
provide its definition in this post.

For the operation '(void)r++', the 'semantics, pre/post conditions'
column says:
'equivalent to (void)++r'
Here, in '(void)r++', what does it mean to prefix 'r++' with (void)
and what is meant by saying 'equivalent to (void)++r' ? If necessary
give some example.

Kindly explain.

Thanks
V.Subramanian

 

[Öö Tiib]

In the ISO/IEC 14882:2003 document, in section '24.1.1 Input
Iterators' in page 517, in Table 72, I need some clarifications/
explanations.

For the operation 'a == b', the 'semantics, pre/post conditions'
column says:
'== is an equivalence relation over its domain'
Where can I find the definition of 'equivalence relation' in the
standard document ? If it is not defined in this document, kindly
provide its definition in this post.

'Equivalence relation' is mathematical term. Use google or wikipedia
to find definitions for terms that are not defined in documents that
you read.