-module(foo).
-export([bar/1]).

bar(X) ->
  case correct(X) of
    42 -> f(X)
  end.

correct(X) ->
  case f(X) of
    1 -> 42;
    Y when Y > 5 -> 42;
    _ -> 0
  end.

f(X) ->
  case X of
    6 -> 1;
    1 -> 7;
    3 -> 5;
    _ -> 23
  end.