40 ILCS 5/5-111

"Future entrant": (a) A person employed by a city as a policeman for the first time on or after the effective date; (b) A former policeman of a city who reenters the police service on or after the effective date; and (c) Effective January 1, 1960, a policeman who qualifies as a future entrant under the "Park Policemen's Annuity Act", whose employment as a policeman has been transferred to the police service of the city as a result of the "Exchange of Functions Act of 1957".