The documentation on Operator-Input Forms shows the following example
which suggests that there is an alternative, convenient, operator-style, tidy technique for inputting lists. However, there is not enough clarity in the example to determine what that technique or operator might be. I tried
e12, but they both result in
Times[e1,e2], somewhat predictably, since space normally denotes multiplication in Mathematica notebooks.
Any ideas whether there is an operator form for inputting lists? What does the documentation mean in this case?