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Again it looks like I am answering my own question. It appears that the underscore is a necessary character.
So the solution to my underscore problem is to type the programs in the terminal mode where the underscore appears
and then execute the programs in IDLE where a blank space appears for the underscore. If I type the programs
initially with IDLE, a blank space appears for the underscore, but the underscore character is NOT in memory,
I must first type the programs in the terminal mode and execute them in IDLE.
Although this procedure is "unconventional", it works every time.
