( a , b ) <annotation-xml encoding="MathML-Content" id="p1.1.m1.1b"> <interval closure="open" id="p1.1.m1.1.6.1.cmml" xref="p1.1.m1.1.6"> <ci id="p1.1.m1.1.2.cmml" xref="p1.1.m1.1.2">𝑎</ci> <ci id="p1.1.m1.1.4.cmml" xref="p1.1.m1.1.4">𝑏</ci> </interval> </annotation-xml> {\displaystyle{\displaystyle(\NVar{a},\NVar{b})}}