NOVELTY - Composition comprises: 2,3,3,3-tetrafluoropropene (HFO-1234yf) and cyclopropane; HFO-1234yf and propylene; HFO-1234yf, 1,1-difluoroethane (HFC-152a) and cyclopropane; HFO-1234yf, HFC-152a and propane; or HFO-1234yf, 1,1,1,2-tetrafluoroethane (HFC-134a) and cyclopropane.    USE - The composition is useful: in refrigeration, air-conditioning and heat pump systems; as heat transfer fluids in processes for producing cooling or heat; as foam blowing agents and aerosol propellants (all claimed), in fire suppression and fire extinguishing agents.    ADVANTAGE - The composition provides unique characteristics to meet the demands of low or zero ozone depletion potential and lower global warming potential as compared to current refrigerants.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for:    (1) a process to produce cooling comprising condensing the composition and evaporating the composition in the vicinity of a body to be cooled;    (2) a process to produce heat comprising condensing the composition in the vicinity of a body to be heated and evaporating the composition;    (3) a method for replacing 1,1,1,2-tetrafluoroethane (R134a), chlorodifluoromethane (R22), dichlorodifluoromethane (R12), a blend of pentafluoroethane (R125) (44 wt.%), 1,1,1-trifluoroethane (R143a) (52 wt.%) and R134a (4 wt.%) (R404A), a blend of R125 (50 wt.%) and difluoromethane (R32) (50 wt.%) (R410A), a blend of R134a (52 wt.%), R125 (25 wt.%) and R32 (23 wt.%) (R407C), a blend of octafluoropropane (R218), R134a and isobutene (R413A), a blend of R125 (46.6 wt.%), R134a (50 wt.%) and n-butane (3.4 wt.%) (R417A), blends of R125, R134a, isobutene in differing component concentrations (R422A, R422B, R422C and R422D), a blend of R134a (52.5 wt.%) and 1,1,1,2,3,3,3-heptafluoropropane (R227ea) (47.5 wt.%) (R423A), a blend of R125, R134a, isobutane, n-butane, and isopentane (R 424A), a blend of R125, R134a, n-butane, and isopentane) (R426A), a blend of R125, R143a, propane and isobutane) (R428A); a blend of difluoro-1,1-ethane (R152a) and isobutane (R430A), a blend of R125 (63.2 wt.%), R134a (16 wt.%), R143a (18 wt.%) and isobutane (2.8 wt.%) (R434A), a blend of R125 (19.5 wt.%), R134a (78.5 wt.%), n-butane (1.4 wt.%) and n-pentane (0.6 wt.%) (R437A), a blend of R32 (8.5 wt.%), R125 (45 wt.%), R134a (44.2 wt.%), n-butane (1.7 wt.%) and isopentane (0.6 wt.%) (R438A), a blend of R125 (50 wt.%) and R143a (50 wt.%) (R507A) and a blend of chloropentafluoroethane (CFC-115) (51.2 wt.%) and chlorodifluoromethane (HCFC-22) (48.8 wt.%) (R502) in a system that uses, used or was designed to use R134a, R22, R12, R404A, R410A, R407C, R413A, R417A, R422A, R422B, R422C and R422D, R423A, R424A, R426A, R428A, R430A, R434A, R437A, R438A, R507A and R502, where the method comprises providing the composition to the system;    (4) a refrigeration, air-conditioning or heat pump apparatus containing the composition;    (5) a stationary air conditioning apparatus containing the composition;    (6) a stationary refrigeration system containing the composition;    (7) a foam blowing agent comprising the composition;    (8) a method of forming foam comprising: adding to a foamable composition the composition; and reacting the foamable composition under conditions effective to form foam;    (9) a sprayable composition comprising the composition; and    (10) a process for producing aerosol products comprising adding the composition to active ingredients in an aerosol container, where the composition functions as a propellant.