The PERFORM statement executes one or more procedures.  It returns
  control to the end of the PERFORM statement when procedure execution
  ends.

  Format 1 -

   PERFORM [first-proc [ { THRU    } end-proc ]]
           [           [ { THROUGH }          ]]

    [ stment  END-PERFORM ]

  Additional Information (explode) :

• first-proc
• end-proc
• stment