Another `if-then-fi` variant that offers some convenience
from time to time is the `If`(*cond*, *exprtrue*,
*exprfalse*). This function returns the result of evaluating
*exprtrue* if the boolean conditional *cond* is true or it
returns the result of evaluating *exprfalse* if *cond* is false.

> x := 101: # x is just some number > round_up := If( mod(x, 2)=0 , x/2, (x+1)/2 ); round_up := 51 > x := 44: > round_up := If( mod(x, 2)=0 , x/2, (x+1)/2 ); round_up := 22