{1000, 990, "263409560461970212832400"},
	} {
		if got := z.Binomial(test.n, test.k).String(); got != test.want {
			t.Errorf("Binomial(%d, %d) = %s; want %s", test.n, test.k, got, test.want)
		}
	}
}

func BenchmarkBinomial(b *testing.B) {
	var z Int
	for i := 0; i < b.N; i++ {
		z.Binomial(1000, 990)
	}
}

// Examples from the Go Language Spec, section "Arithmetic operators"

                return size;
              }
            };
          }
        };
      }

      @Override
      public int size() {
        return IntMath.binomial(index.size(), size);
      }

      @Override
      public String toString() {
        return "Sets.combinations(" + index.keySet() + ", " + size + ")";
      }
    };
  }

                return size;
              }
            };
          }
        };
      }

      @Override
      public int size() {
        return IntMath.binomial(index.size(), size);
      }

      @Override
      public String toString() {
        return "Sets.combinations(" + index.keySet() + ", " + size + ")";
      }
    };
  }