The join example as follows so that it is compatible with the current postprocessing abilities of wrappers.
<&f(I,S) entry {<&Toid title T> <&Aoid author A> <&Aboid abstract B>}>
:- <&I inspecentry {<&Toid title T> <&Aoid author A>}>@inspec
AND <&S sybasentry { <&Aboid abstract B>}>@sybase.
author(f(I,S), W)
:- author(I, W)@inspec
AND author(S, W)@sybase.
</PRE>
*Query*
<P>
<PRE>
<&X ans V> :- <&X entry V>@med AND author(X,cia)@med.
</PRE>
*Mediator Processing*
<UL>
<LI>SKOLEMIZED QUERY:
<PRE>
<X_0 ans V_0> :-
<X_0 entry V_0>@med
AND author(X_0, cia)@med.
</PRE>
<LI>SKOLEMIZED RULE:
<PRE>
<f(I_1,S_1) entry {<Toid_1 title T_1> <Aoid_1 author A_1> <Aboid_1 abstract B_1> }> :-
<I_1 inspecentry {<Toid_1 title T_1> <Aoid_1 author A_1>}>@inspec
AND <S_1 sybasentry {<OID0_1 title T_1> <Aboid_1 abstract B_1>}>@sybase.
</PRE>
<LI>SKOLEMIZED RULE:
<PRE>
author(f(I_2,S_2), W_2) :-
author(I_2, W_2)@inspec
AND author(S_2, W_2)@sybase.
</PRE>
<LI>SKOLEMIZED AND NORMALIZED QUERY:
<PRE>
<X_0 ans V_0> :-
<X_0 entry V_0>@med
AND author(X_0, cia)@med.
</PRE>
<LI>STATISTICS
<PRE>
Unifiers
UNIFIER
USED RULE 2
USED RULE 1
MAPPING X_0 -> f(I_1,S_1)
MAPPING I_2 -> I_1
MAPPING S_2 -> S_1
MAPPING W_2 -> cia
DEFINITION V_0 => {<Toid_1 title T_1> <Aoid_1 author A_1> <Aboid_1 abstract B_1> }
</PRE>
<LI>DATAMERGE RULES
<PRE>
<f(I_1,S_1) ans {<Toid_1 title T_1> <Aoid_1 author A_1> <Aboid_1 abstract B_1> }> :-
author(I_1, cia)@inspec
AND author(S_1, cia)@sybase
AND <I_1 inspecentry {<Toid_1 title T_1> <Aoid_1 author A_1>}>@inspec
AND <S_1 sybasentry {<OID0_1 title T_1> <Aboid_1 abstract B_1>}>@sybase.
SITECHARGE: sybase => 0, inspec => 0,
</PRE>
<LI>DATAMERGE GRAPH
<PRE>
TOP consists of 1 CONSTRUCTs
TERM 0
CONSTRUCTOR
PATTERN: <f(I_1,S_1) ans {<Toid_1 title T_1> <Aoid_1 author A_1> <Aboid_1 abstract B_1> }>
JOIN on variables T_1 (clmn 2 of left op, clmn 1 of right op)
OUTPUT: [I_1 Toid_1 T_1 Aoid_1 A_1 S_1 Aboid_1 B_1 ]
LEFT JOIN OPERAND
EXTRACT OUTPUT: [I_1 Toid_1 T_1 Aoid_1 A_1 ]
on column 0
QUERY to source inspec
OUTPUT: [answer ]
QUERY STRING: <bindings { <bindI_1 I_1> <bindToid_1 Toid_1> <bindT_1 T_1> <bindAoid_1 Aoid_1> <bindA_1 A_1> }> :- <I_1 inspecentry {<Toid_1 title T_1> <Aoid_1 author A_1>}>@inspec AND author(I_1, cia)@inspec.
RIGHT JOIN OPERAND
EXTRACT OUTPUT: [S_1 T_1 Aboid_1 B_1 ]
on column 0
QUERY to source sybase
OUTPUT: [answer ]
QUERY STRING: <bindings { <bindS_1 S_1> <bindT_1 T_1> <bindAboid_1 Aboid_1> <bindB_1 B_1> }> :- <S_1 sybasentry {<OID0_1 title T_1> <Aboid_1 abstract B_1>}>@sybase AND author(S_1, cia)@sybase.
</PRE>
</UL>
</UL>
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