true.

?- tryThis.
Type in something followed by a period: 
|: chocolate.
You typed in: chocolate
true.

?- tryThis.
Type in something followed by a period: 
|: vanilla.
You typed in: vanilla
true.

?- tryThis.
Type in something followed by a period: 
|: 13
|: .
You typed in: 13
true.

?- tryThis.
Type in something followed by a period: 
|: 13.14.
You typed in: 13.14
true.

?- tryThis.
Type in something followed by a period: 
|: 13
|: 14
|: .
ERROR: Stream user_input:0:41 Syntax error: Operator expected
?- .
ERROR: Stream user_input:0:44 Syntax error: Unexpected end of clause
?- 
|    .
ERROR: Stream user_input:0:47 Syntax error: Unexpected end of clause
?- .
ERROR: Stream user_input:0:49 Syntax error: Unexpected end of clause
?- tryThis.
Type in something followed by a period: 
|: UhOh.
You typed in: _L124
true.

?- member(1, What).
What = [1|_G673] ..

?- member(1, What).
What = [1|_G593] ;;
What = [_G592, 1|_G596] ;;
What = [_G592, _G595, 1|_G599] ;;
What = [_G592, _G595, _G598, 1|_G602] ;;
What = [_G592, _G595, _G598, _G601, 1|_G605] ..

?- halt.