### Rules to create a 365-day calendar.
### This version creates only 1 day per month because
### the name attribute is attached to the year. 

### Also, in this production the value of 2003 is actually attached
### to the state, not the year. If there is to be only one year in the
### calendar, this might not matter, but if there are to be more years,
### then the value needs to be attached to the year object to keep
### everything straight.
sp {initialize*calendar
    (state <s> ^superstate nil)
	-->                                       
    (<s> ^year <y> ^value 2003)}

sp {initialize*months
    (state <s> ^year <y>)
	-->
    (<y> ^month <m1> ^name january)
    (<y> ^month <m2> ^name february)
    (<y> ^month <m3> ^name march)
    (<y> ^month <m4> ^name april)
    (<y> ^month <m5> ^name may)
    (<y> ^month <m6> ^name june)
    (<y> ^month <m7> ^name july)
    (<y> ^month <m8> ^name august)
    (<y> ^month <m9> ^name september)
    (<y> ^month <m10> ^name october)
    (<y> ^month <m11> ^name november)}

sp {initialize*31day*length
    (state <s> ^year <y>)
    (<y> ^month <m>)
    (<m> ^name << january march may july august october december >> )
	-->
    (<m> ^days 31)}

sp {initialize*30day*length
    (state <s> ^year <y>)
    (<y> ^month <m>)
    (<m> ^name << september april june november >> )
	-->
    (<m> ^days 30)}

sp {initialize*february*length
    (state <s> ^year <y>)
    (<y> ^month <m>)
    (<m> ^name february)
	-->
    (<m> ^days 28)}

sp {initialize*first*days
    (state <s> ^year <y>)
    (<y> ^month <m>)
	-->
    (<m> ^date 1)}

sp {initialize*remaining*days
    (state <s> ^year <y>)
    (<y> ^month <m>)
    (<m> ^days <len>)
    (<m> ^date { <d> < <len> } )
	-->
    (<m> ^date ( + <d> 1 ))}