############################################################# # Computing True and Expected Valuations of Cross functions # ############################################################# # To determine the metric trees associated to all extremal curves we must settle the differences between expected and true valuations. In order to do so, we # 1) compute the valuations of all Cross functions from all four expressions of Crosses as differences of Yoshidas, whenever possible. # 2) list the Crosses with undertermined valuations for each cone. # 3) Create dictionaries of valuations for Crosses for each cone. # 4) compute true valuation of Crosses. # 5) compute the expected valuation of Crosses. # 6) verify the differences on examples # For 1), we pick all 4 ways of writing a given Cross function as differences of Yoshidas, and determine if on a given cone, one of these ways gives no ties on the center of mass, hence determining the true valuation of the Cross function on the whole cone (it will agree with the valuation of a Yoshida function). # If all ways yield tie, we record 'None' as the true valuation of the given Cross function. # For 5): When computing expected valuations, we consider only the Cross with 'None' as true valuations and determine the largest among the expected valuations for each way. This would be our expected valuation. # For 6): we compute parameters in ds to find differences between true and expected valuations. ########################################################################### # Setting up the ambient rings with the W(E6) action. ########################################################################### # A list of variables d_1, ..., d_6 for the coefficients ds = [var("d%s"%i) for i in range(1,7)] # A list of variables E_1, ..., E_6 Es = [var("E%s"%i) for i in range(1,7)] # A list of variables F_12, ..., F_56 Fs = [var("F%s%s"%(i,j)) for i in range(1,7) for j in range(1,7) if i < j] # A list of variables G_1, ..., G_6 Gs = [var("G%s"%i) for i in range(1,7)] # A list of variables X_12, ..., X_65 Xs = [var("X%s%s"%(i,j)) for i in range(1,7) for j in range(1,7) if i != j] # A list of variables Y_123456, ..., Y_162534 Ys = [var("Y%s%s%s%s%s%s"%(i,j,k,l,m,n)) for i in range(1,7) for j in range(1,7) for k in range(1,7) for l in range(1,7) for m in range(1,7) for n in range(1,7) if i