In {{cljs.core/pr-sequential-writer}}, there is a {{loop}} that initializes {{n}} to be the result of {{dec}}, and upon {{recur}}, {{dec}} is also caused to form the next value of {{n}}.
In the scope of that {{loop}} there is an expression
(or (nil? n) (not (zero? n)))
which can be simplified to
(not (zero? n))
because {{n}} is known to be a number, and cannot be {{nil}}.
