range 1..2
 range ref type: Math::Range
 object address: Math::Range=ARRAY(0x123ABC)
 range is sharply defined: 1
 range keeps point 0.8: 0
 range keeps point 1.3: 1
 range keeps point 2.0: 1
range 1.5..undef
 range ref type: Math::Range
 object address: Math::Range=ARRAY(0x123ABC)
 range is sharply defined: 0
 range keeps point 0.8: 0
 range keeps point 1.3: 0
 range keeps point 2.0: 1
