Abel sum noun1 •Given a power series f(x)=∑ₙ₌₀ ᪲a_nxⁿ that is convergent for real x in the open interval (0, 1), the value lim _(x→1⁻)∑ₙ₌₀ ᪲a_nxⁿ, which is assigned to f(1)=∑ₙ₌₀ ᪲a_n by the Abel summation method (or A-method).lim _(x→1-0)∑ₙ₌₀ ᪲a_nxⁿ. The existence of the Abel sum is ascertained when the series in question is known to be summable (C, r) for some value of r. — 1967 formsAbel sums