The following query uses one RSE that includes five out of the
       six optional elements of an RSE. DEC DATATRIEVE processes the
       query far faster than if nested FOR loops were used:

       DTR> DEFINE PROCEDURE CROS
       DFN> READY YACHTS
       DFN> PRINT BUILDER, RIG, A.RIG OF
       DFN>   A IN YACHTS CROSS YACHTS OVER BUILDER WITH
       DFN>   RIG GT A.RIG REDUCED TO BUILDER, RIG, A.RIG
       DFN> END_PROCEDURE

       DTR> :CROS

       MANUFACTURER  RIG    RIG

        AMERICAN    SLOOP  MS
        CHALLENGER  SLOOP  KETCH
        GRAMPIAN    SLOOP  KETCH
        IRWIN       SLOOP  KETCH
        ISLANDER    SLOOP  KETCH
        NORTHERN    SLOOP  KETCH
        PEARSON     SLOOP  KETCH

       DTR>