Consolidation of derivation rules on Section B.2.3

DR3 and DR4 could be combined in one as below:

• DR3 from "If two relationships p(a,b):S and q(b,c):T exist, with S being a structural relationship and T being a dependency relationship, then a relationship r(a,c):T can be derived." to "If two relationships p(a,b):S and q(b,c):T exist, with S being a structural relationship and T being a dependency relationship, then a relationship r(a,c):T, with the same direction as q, can be derived"
• remove DR4