Name Errors/Static/Arity

Synopsis The number of arguments of an operator differ from what is required.

Description Various operators like Rascal:Relation/Composition, Rascal:Relation/TransitiveClosure and Rascal:Relation/ReflexiveTransitiveClosure expect binary relations or tuples as arguments.

Examples This composition is correct:

rascal>{<1,10>, <2,20>} o {<10,100>, <20, 200>};
rel[int,int]: {
  <2,200>,
  <1,100>
}

This is not, since the first argument has arity 3:

rascal>{<1,5,10>, <2,6,20>} o {<10,100>, <20, 200>};
|stdin:///|(39,3,<1,39>,<1,42>): Expected arity : 2, unequal to 3

These transitive closures are correct:

rascal>{<1,2>, <2,3>,<4,5>}+
rel[int,int]: {
  <4,5>,
  <1,2>,
  <1,3>,
  <2,3>
}
rascal>{<1,2>, <2,3>,<4,5>}*
rel[int,int]: {
  <4,4>,
  <4,5>,
  <5,5>,
  <2,2>,
  <1,2>,
  <1,3>,
  <2,3>,
  <1,1>,
  <3,3>
}

But these are incorrect:

rascal>{<1,2,3>, <2,3,4>,<4,5,6>}+
|stdin:///|(23,1,<1,23>,<1,24>): Expected arity : 2, unequal to 3
rascal>{<1,2,3>, <2,3,4>,<4,5,6>}*
|stdin:///|(23,1,<1,23>,<1,24>): Expected arity : 2, unequal to 3

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