Typo in hw03.md (#20)

homework/hw03.md

@@ -54,7 +54,7 @@ x
 λ> Lambda "s" (Lambda "z" (App (Var "s") (App (Var "s") (Var "z"))))
 (\s.(\z.(s (s z))))
 ```
-So the symbol $\lambda$ is displayed as `\`. Variables are displays as their names. Applications
+So the symbol $\lambda$ is displayed as `\`. Variables are displayed as their names. Applications
 are displayed as `(e1 e2)`
 with a space separating expressions `e1,e2`
 and $\lambda$-abstractions as `(\x.e)`.