read `ThreeQuarterPlane.txt`:

a:=53:
b:=141:




ope:=FindOperGK(a,b,n,N,20):

n0:=ope[2]:
ope:=ope[1]:

print(`Consider f(n):= the number of ways of walking from the origin to the point`, [a,b], ` in the QUARTER-PLANE, with n steps using the Kreweras steps {[-1,0],[0,-1],[1,1]}`):
print(`Then f(n)=0 for n<`, n0, `and defining`, g(n)=f(n0-1+n), `g(n)  is annihilated by an operator of order`, degree(ope,N), `and degree in n of the  coefficients`, degree(numer(ope),n)):
print(``):
print(`Here it is`):
print(``):
lprint(ope):




print(``):
print(`--------------------------`):
print(`This took`, time(), `seconds. `):

quit: