Question 905688
{{{x<>11}}}+{{{x<>0}}}=({{{-infinity}}},{{{0}}})U({{{0}}},{{{11}}})U({{{11}}},{{{infinity}}})
{{{x<>-11}}}+{{{x<>0}}}=({{{-infinity}}},{{{-11}}})U({{{-11}}},{{{0}}})U({{{0}}},{{{infinity}}})
{{{x<>0}}}=({{{-infinity}}},{{{0}}})U({{{0}}},{{{infinity}}})