This calculator application offers two input syntax modes for your convenience.
The first mode allows you to simply input a formula, such as '2*(3+4)', and then press 'Enter' to compute the result.
Alternatively, the second mode enables you to define custom functions, like 'add(x)=x+5'. Once defined, you can seamlessly integrate these functions into subsequent formulas. It's important to note that function names must consist of at least two letters.