;Task:
Demonstrate the different syntax and semantics provided for calling a function. 


This may include:
:* &nbsp; Calling a function that requires no arguments
:* &nbsp; Calling a function with a fixed number of arguments
:* &nbsp; Calling a function with [[Optional parameters|optional arguments]]
:* &nbsp; Calling a function with a [[Variadic function|variable number of arguments]]
:* &nbsp; Calling a function with [[Named parameters|named arguments]]
:* &nbsp; Using a function in statement context
:* &nbsp; Using a function in [[First-class functions|first-class context]] within an expression
:* &nbsp; Obtaining the return value of a function
:* &nbsp; Distinguishing built-in functions and user-defined functions
:* &nbsp; Distinguishing subroutines and functions
;* &nbsp; Stating whether arguments are [[:Category:Parameter passing|passed]] by value or by reference
;* &nbsp; Is partial application possible and how

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This task is ''not'' about [[Function definition|defining functions]].
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