Source code in the logo programming language

to max :a :b
output ifelse :a > :b [:a] [:b]
end

print reduce "max [...]

to max [:inputs] 2
if emptyp :inputs ~
   [(throw "error [not enough inputs to max])]
output reduce [ifelse ?1 > ?2 [?1] [?2]] :inputs
end

to bigger :a :b
  output ifelse [greater? :a :b] [:a] [:b]
end

to max :lst
  output reduce "bigger :lst
end