premise: His tone brought the blood into Ellis Duncan 's face .<br>The lad opened his lips quickly , as if for an angry retort , but as quickly closed them again with a set firmness oddly like Timothy Robinson 's own .<br>`` When I heard that lazy , worthless father of yours was dead , I expected you and your mother would be looking to me for help , '' Timothy Robinson went on harshly .<br>`` But you 're mistaken if you think I 'll give it .<br>You 've no claim on me , even if your father was my half-brother -- no claim at all .<br>And I 'm not noted for charity . ''<br>Timothy Robinson smiled grimly .
hypothesis: robinson is Duncan's uncle.
reason: if he is the half brother of Duncan's father, then he is Duncan's uncle