I used the word "swell" to describe the phenomenon that in Haskell pointers can consume vast amounts of memory, especially on 64 bit architectures. For example type (Bool,Bool,Bool,Bool,Bool,Bool,Bool,Bool), one byte of information, will take 136 bytes, unless you fight the laziness feature with ! and UNPACK. Okay, this is an evil contrived example, but you get the idea. It is not generally accepted nomenclature.If I change my Map to Strict and call rCount directly( don’t use mapM_ ) the memory will not swell.