Use if (foo) return bar(); return baz(); instead of if (foo) { return bar(); } else { return baz(); } This makes the code a little bit more readable. --- ginac/normal.cpp | 40 ++++++++++++++++++++-------------------- 1 files changed, 20 insertions(+), 20 deletions(-) diff --git a/ginac/normal.cpp b/ginac/normal.cpp index 6392e3f..09773d3 100644 --- a/ginac/normal.cpp +++ b/ginac/normal.cpp @@ -1647,8 +1647,9 @@ static ex gcd_pf_pow_pow(const ex& a, const ex& b, ex* ca, ex* cb) const ex& exp_a = a.op(1); ex pb = b.op(0); const ex& exp_b = b.op(1); + + // a = p^n, b = p^m, gcd = p^min(n, m) if (p.is_equal(pb)) { - // a = p^n, b = p^m, gcd = p^min(n, m) if (exp_a < exp_b) { if (ca) *ca = _ex1; @@ -1662,31 +1663,30 @@ static ex gcd_pf_pow_pow(const ex& a, const ex& b, ex* ca, ex* cb) *cb = _ex1; return power(p, exp_b); } - } else { - ex p_co, pb_co; - ex p_gcd = gcd(p, pb, &p_co, &pb_co, false); - if (p_gcd.is_equal(_ex1)) { - // a(x) = p(x)^n, b(x) = p_b(x)^m, gcd (p, p_b) = 1 ==> - // gcd(a,b) = 1 + } + + ex p_co, pb_co; + ex p_gcd = gcd(p, pb, &p_co, &pb_co, false); + // a(x) = p(x)^n, b(x) = p_b(x)^m, gcd (p, p_b) = 1 ==> gcd(a,b) = 1 + if (p_gcd.is_equal(_ex1)) { if (ca) *ca = a; if (cb) *cb = b; return _ex1; // XXX: do I need to check for p_gcd = -1? - } else { - // there are common factors: - // a(x) = g(x)^n A(x)^n, b(x) = g(x)^m B(x)^m ==> - // gcd(a, b) = g(x)^n gcd(A(x)^n, g(x)^(n-m) B(x)^m - if (exp_a < exp_b) { - return power(p_gcd, exp_a)* - gcd(power(p_co, exp_a), power(p_gcd, exp_b-exp_a)*power(pb_co, exp_b), ca, cb, false); - } else { - return power(p_gcd, exp_b)* - gcd(power(p_gcd, exp_a - exp_b)*power(p_co, exp_a), power(pb_co, exp_b), ca, cb, false); - } - } // p_gcd.is_equal(_ex1) - } // p.is_equal(pb) + } + + // there are common factors: + // a(x) = g(x)^n A(x)^n, b(x) = g(x)^m B(x)^m ==> + // gcd(a, b) = g(x)^n gcd(A(x)^n, g(x)^(n-m) B(x)^m + if (exp_a < exp_b) { + ex pg = gcd(power(p_co, exp_a), power(p_gcd, exp_b-exp_a)*power(pb_co, exp_b), ca, cb, false); + return power(p_gcd, exp_a)*pg; + } else { + ex pg = gcd(power(p_gcd, exp_a - exp_b)*power(p_co, exp_a), power(pb_co, exp_b), ca, cb, false); + return power(p_gcd, exp_b)*pg; + } } static ex gcd_pf_pow(const ex& a, const ex& b, ex* ca, ex* cb) -- 1.5.6 Best regards, Alexei -- All science is either physics or stamp collecting.