v_R
i1 : R = QQ[t_1..t_4] o1 = R o1 : PolynomialRing
i2 : symbol t_1 o2 = t 1 o2 : IndexedVariable
i3 : oo_R o3 = t 1 o3 : R
The source of this document is in Macaulay2Doc/operators/underscore.m2:261:0.