-(def-source-transform first (x) `(car ,x))
-(def-source-transform rest (x) `(cdr ,x))
-(def-source-transform second (x) `(cadr ,x))
-(def-source-transform third (x) `(caddr ,x))
-(def-source-transform fourth (x) `(cadddr ,x))
-(def-source-transform fifth (x) `(nth 4 ,x))
-(def-source-transform sixth (x) `(nth 5 ,x))
-(def-source-transform seventh (x) `(nth 6 ,x))
-(def-source-transform eighth (x) `(nth 7 ,x))
-(def-source-transform ninth (x) `(nth 8 ,x))
-(def-source-transform tenth (x) `(nth 9 ,x))
+(define-source-transform first (x) `(car ,x))
+(define-source-transform rest (x) `(cdr ,x))
+(define-source-transform second (x) `(cadr ,x))
+(define-source-transform third (x) `(caddr ,x))
+(define-source-transform fourth (x) `(cadddr ,x))
+(define-source-transform fifth (x) `(nth 4 ,x))
+(define-source-transform sixth (x) `(nth 5 ,x))
+(define-source-transform seventh (x) `(nth 6 ,x))
+(define-source-transform eighth (x) `(nth 7 ,x))
+(define-source-transform ninth (x) `(nth 8 ,x))
+(define-source-transform tenth (x) `(nth 9 ,x))