But
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Define a formula with real or complex values based on its mathematical expression.

The formula can be used in a later command as a function/formula argument or evaluated with particular values of the variables.

In many applications, this formula can be tabulated for particular values using the CALC_FONC_INTERP [:external:ref:`U4.32.01 <U4.32.01>`] command, which produces a function or function_c concept such as DEFI_FONCTION [:ref:`U4.31.02 <U4.31.02>`] or DEFI_NAPPE [:ref:`U4.31.03 <U4.31.03>`].