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# Custom function to make a latex 'equation' string from a-invariants
#
# assume that [a1,a2,a3] are one of the 12 reduced triples.
# This is the same as latex(EllipticCurve(ainvs)).replace("
# ","").replace("{3}","3").replace("{2}","2"), i.e. the only
# difference is that we have x^3 instead of x^{3} (and x^2 instead of
# x^{2} when a2!=0), and have no spaces. I checked this on all curves
# of conductor <10000!
def latex_equation(ainvs):
a1, a2, a3, a4, a6 = [int(a) for a in ainvs]
return ''.join([r'\(y^2',
'+xy' if a1 else '',
'+y' if a3 else '',
'=x^3',
'+x^2' if a2 == 1 else '-x^2' if a2 == -1 else '',
'{:+}x'.format(a4) if abs(a4) > 1 else '+x' if a4 == 1 else '-x' if a4 == -1 else '',
'{:+}'.format(a6) if a6 else '',
r'\)'])
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