Select language: english | cesky | deutsch | italiano | simplified chinese | traditional chinese | hindi
Concept:
English word:
Home

leap year (LeapYear)

The Class of all leap years. These are years which are either (i.) evenly divisible by 4 and not by 100 or (ii.) evenly divisible by 400 (this latter case is known as a leap century).

Ontology

SUMO / TEMPORAL-CONCEPTS

Superclass(es)

[tree]
entity
is subclass of
  abstract  
is subclass of
  quantity  
is subclass of
  physical quantity  
is subclass of
  constant quantity  
is subclass of
  time measure  
is subclass of
  time position  
is subclass of
  time interval  
is subclass of
  year  
is subclass of
  leap year  

Axioms (3)

If leap is an instance of leap year and leap is equal to "number year(s)", then 
(=>
      (and
            (instance ?LEAP LeapYear)
            (equal
                  ?LEAP
                  (MeasureFn ?NUMBER Year)))
      (or
            (and
                  (equal
                        (RemainderFn ?NUMBER 4)
                        0)
                  (not
                        (equal
                              (RemainderFn ?NUMBER 100)
                              0)))
            (equal
                  (RemainderFn ?NUMBER 400)
                  0)))
If "the month february" is equal to month and year is not an instance of leap year, then duration of month is " day duration(s)". 
(=>
      (and
            (equal
                  (MonthFn February ?YEAR)
                  ?MONTH)
            (not
                  (instance ?YEAR LeapYear)))
      (duration
            ?MONTH
            (MeasureFn 28 DayDuration)))
If "the month february" is equal to month and year is an instance of leap year, then duration of month is " day duration(s)". 
(=>
      (and
            (equal
                  (MonthFn February ?YEAR)
                  ?MONTH)
            (instance ?YEAR LeapYear))
      (duration
            ?MONTH
            (MeasureFn 29 DayDuration)))