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These  menu functions provides the user by  the following 
possibilities:
1. to define numerical value of  QCD-lambda5 parameter.
  The QCD strong coupling alpha(Q) is calculated in the (NNLO)
order (see 9.5a [*]). For Q>Mtop and Q<Mb lambda-6 and 
lambda-4  are calculated according to (9.7) [*].
  The alpha(Q) also can be defined via  pdf-file (see manual). 
Thus, if the user activate a distribution function which 
contains his own definition of alpha(Q), then the first line of
menu contains the message "Defined via pdf-file". 

2. to define dependence of strong coupling on the phase-space 
point. CalcHEP substitutes the QCD strong coupling constant as
a function of the Q-scale. Q-scale should be defined as an 
algebraic expression which can  contain float point numbers and
some special set of phase-space functions (see help for 
VEGAS/Set~distributions or Manual).  Standard C float point 
functions like  sqrt(x) and  fabs(x) also are permitted here.

3. to display the alpha(Q) plots for the region of 'Q' defined
by the user. 

*)Eur. Phys. J. C 15(2000) pp.85,86

