Largest number

That will ONLY work if a, b and c are values (or sets of values such as array or matrices): you'll get the largest of any of the values and/or array- and/or matrix-elements.

If a, b and c are really functions, you'll need a litte more.

Success!
Luc

May be so

a(x):=…

b(x):=…

c(x):=…

d(x):=max(a(x), b(x), d(x))

And what Valery shows (above, Thanks Valery!) is one possibility of 'a little more'.

Essentially what goes on there is that a(x), b(x) etc are numbers, each corresponding to a call to the d(x) function.

Luc