# Drawing a relation

I am doing a past paper, and one of the question is:

Let $A =${$cat, dog, mouse, bird$}, and let $R$ be the binary relation on $A$ given by:

$R =${($x, y$): $x$ and $y$ have no letter in common}.

Draw $R$

I have a limited understanding of relations (after watching videos and reading books on reflexive, symmetric, transitive properties), but all the past papers I have ask me to draw a relation and I have no idea how where to start, and can not seem to find any simple resources. Please could someone guide me on this.

Edit (my attempt):

• Put a labeled dot on paper for each of the four species, connect two by a line when they are related by $R$. Jan 6 '18 at 14:57
• @EthanBolker Please see my edit in the OP, would a drawing like that be correct for the question? Jan 6 '18 at 15:33
• obviously 'Bird' and 'Dog' don't satisfy our relation Jan 6 '18 at 15:35
• Yes, it's right now. Jan 6 '18 at 16:17

$\{ (cat, dog), (mouse, bird), (bird, cat), (cat,mouse) \}$

Every pair has no letter in common, can you see it ?

• So would my drawing in the OP (just added it now) be correct? Jan 6 '18 at 15:35
• It isn't, 'Bird' and 'Dog' shared -d-. Jan 6 '18 at 15:36
• Oops, my English is too bad haha. Please see updated. That drawing would be the correct answer for the question asked? Jan 6 '18 at 15:38
• It is correct now. Jan 6 '18 at 15:39
• I'm sorry, i misunderstood you, you are right, it wouldn't connect to and other word. Jan 6 '18 at 15:49