class UEDGE{NTP} < $EDGE{NTP}, $HASH
****
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Ancestors
$HASH $IS_EQ $EDGE{_} $STR
COMPARE{_}



Public


Readable Attributes
attr first, second: NTP;
attr first, second: NTP;

Features
create(f,s: NTP): SAME
elt_str(e: NTP): STR
hash:INT
**** A simple hash value computed from the hash values of the components. For this to work, these must either be value types which define hash values or reference types.
is_eq(e:UEDGE{NTP}): BOOL
is_eq(arg: $OB): BOOL .. Included as is_eq
is_reflexive: BOOL
str: STR


Private

elt_eq(e1,e2:ETP):BOOL .. Included as elt_eq
**** The "less than" relation used in the sorting routines. Compares the object "id" by default. May be redefined in descendants.
elt_hash(e:ETP):INT .. Included as elt_hash
**** A hash value associated with an element. Must have the property that if "elt_eq(e1,e2)" then "elt_hash(e1)=elt_hash(e2)". Can be defined to always return 0, but many routines will then become quadratic. Uses object "id" by default. May be redefined in descendants.
elt_lt(e1,e2:ETP):BOOL .. Included as elt_lt
**** The "less than" relation used in the sorting routines. Compares the object "id" by default. May be redefined in descendants.
elt_nil: ETP .. Included as elt_nil
**** Return the nil value. If the element is under $NIL then return e.nil. Otherwise, return void
_
attr first, second: NTP;
is_elt_nil(e:ETP):BOOL .. Included as is_elt_nil
attr first, second: NTP;

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