inheritance.sol

pragma solidity ^0.4.21;

contract A {
    function f() internal {
        g();
    }
    
    function g() internal {
    }
}

contract B is A {
    function f() internal {
        super.f();
    }
    
    function g() internal {
        super.g();
    }
}

contract C is B {
    function fp() public {
        super.f();
    }
}