The first thing to notice is that Banach was not his father's surname, but Banach was given his father's first name. Stefan Greczek was a tax official who was not married to Banach's mother who vanished from the scene after Stefan was baptised, when he was only four days old, and nothing more is known of her.
Ang unang bagay na mapapansin ay na Banach ay hindi kanyang ama apelyido, ngunit Banach ay binibigyan ng kanyang ama unang pangalan. Stefan Greczek ay isang buwis na opisyal ay hindi kasal sa Banach ng ina na vanished mula sa pook na matapos Stefan ay baptised, kapag siya ay lamang ng apat na araw old, at wala ay mas kilala ng kanyang.