K&R C had implied type of 'int' for both arguments and return value, and didn't list the types of arguments on the line specifying function name, argument names and return type:
int foo(x,y)
{
return baz(x,y);
}
bar(x,y,z)
short x;
int z;
{
return x+y+z;
}
baz(x,y,z)
{
return 42;
}