
lp_get_license_challenge(-Challenge)

   Get parameter for computing license key (some external solvers only)

Arguments
   Challenge           Variable

Type
   library(eplex)

Description
	This is only needed for certain OEM versions of external solvers!
    
    	The eplex-library interfaces to an external simplex/MIP solver
	which might require a license to run (e.g. CPLEX, XPRESS-MP).
	Certain versions of these external solvers use a challenge-
	response licensing system. Only in such cases is this predicate
	needed. lp_get_license_challenge/1 returns a value which is used to
	compute a license key. This key is then passed into lp_get_license/2.
	For the details of this procedure you will need to consult the
	documentation of the solver vendor.
    
	If you have a development license of CPLEX or XPRESS-MP, this
	predicate does not need to be called. If called anyway, it fails.
    

Fail Conditions
   Fails if the solver doesn't use a challenge-response licensing system

Examples
   
     ?- ( lp_get_license_challenge(Challenge) ->
	    magic_formula(Challenge, Response),
	    lp_get_license(RuntimeLicenseString, Response)
	;
	    lp_get_license(DevelopmentLicensePath, 0)
	).
    

See Also
   lp_get_license / 2
