which are already in the compiler’s default “include file
search path”, <em>you</em>  must specify compiler options,
such as “<code>-I</code> <code><em>path</em></code> ”,
which are already in the compiler’s default “include file
search path”, <em>you</em>  must specify compiler options,
such as “<code>-I</code> <code><em>path</em></code> ”,