of: a function
is denoted: 
where is called the integrand, and the symbol 
is the element of integration which shows the integration variable, 
with respect to which the integration is to be performed. [M5.1, M5.2]
is: any function 
such that 
[M5.1, M5.2]
is not: unique, since if 
is an indefinite integral of 
then so is 
where 
is an arbitrary constant. For this reason, if is a particular indefinite integral of it is customary to write
where represents an arbitrary additive constant, called the constant of integration. [M5.1, M5.2]
is also called: inverse derivative or anti-derivative or primitive of 
Copyright 1997, The Open University