Application

Application order is set by parentheses and indentation.

We can apply a to b in two different ways:

Using parentheses:

(a b)

Using indentation:

a
  b

It's not necessary to wrap the first expression on the line in parentheses. So the application can look just like this:

a b

Nested application#

Here we apply a to the result of application of b to c.

Using parentheses:

a (b c)

Using indentation:

a
  b c

or:

a
  b
    c

All the expressions below are equivalent:

a (b (c d)) (e (f g))

a
  b (c d)
  e (f g)

a
  b
    c d
  e
    f g

a
  b
    c
      d
  e (f g)

a
  b (c d)
  e
    f
      g