Ruby didn't always had both. `reduce` as an alias for `inject` was introduced in Ruby 1.8.7; `filter` as late as in Ruby 2.6 (just a few years ago, and most of the codebases I saw are still preferring `select`).
Yes, the dictionary is normalized in the last years towards what became industry/mainstream standard names for the concepts, but the statement that initial names were derived from Smalltalk is correct.
Yes, the dictionary is normalized in the last years towards what became industry/mainstream standard names for the concepts, but the statement that initial names were derived from Smalltalk is correct.