using list references in makemove(let' go back to the makemove(function def makemove(boardlettermove) board[moveletter when list value is passed for the board parameterthe function' local variable is really copy of the reference to the listnot copy of the list but copy of the reference still refers to the same list the original reference refers so any changes to board in this function will also happen to the original list even though board is local variablethe makemove(function modifies the original list the letter and move parameters are copies of the string and integer values that you pass since they are copies of valuesif you modify letter or move in this functionthe original variables you used when you called makemove(aren' modified checking if the player has won def iswinner(bole) given board and player' letterthis function returns true if that player has won we use bo instead of board and le instead of letter so we don' have to type as much return ((bo[ =le and bo[ =le and bo[ =leor across the top (bo[ =le and bo[ =le and bo[ =leor across the middle (bo[ =le and bo[ =le and bo[ =leor across the bottom (bo[ =le and bo[ =le and bo[ =leor down the left side (bo[ =le and bo[ =le and bo[ =leor down the middle (bo[ =le and bo[ =le and bo[ =leor down the right side (bo[ =le and bo[ =le and bo[ =leor diagonal (bo[ =le and bo[ =le and bo[ =le)diagonal lines to in the iswinner(function are actually one long return statement the bo and le names are shortcuts for the board and letter parameters these shorter names mean you have less to type in this function rememberpython doesn' care what you name your variables there are eight possible ways to win at tic tac toe you can have line across the topmiddleand bottom rows or you can have line down the leftmiddleor right columns or you can have line over either of the two diagonals post questions to