when left parenthesis is encountereda new node is created and linked into the tree as the left child of the current node we then descend down to the new nodemaking the left child the new current node root token'(root current current the next token is the operand when an operand is encounteredthe data value of the current node is set to contain the operand we then move up to the parent of the current node root token' root current current next comes the plus operator when an operator is encounteredthe data value of the current node is set to the operator new node is then created and linked into the tree as the right child of the current node we descend down to the new node root token'*root *current current the second operand repeats the same action taken with the first operandtoken' root root *current current finallythe right parenthesis is encountered and we move up to the parent of the current node in this casewe have reached the end of the expression and the tree is complete token')root current