$-$ Assign the time variable to the AST below in depth$-$first order and convert it to a quadrature operation. Answer the list of quadrature operations.

The form of the four arithmetic operations is $($ope$,$ dst$,$ src$1,$ src$2).$ where $$ope$$ is an operation, either $$asgn$$ for assignment, $$mul$$ for multiplication, or $$add$$ for addition. The $\text{'}$dst$\text{'},\text{'}$src$1\text{'},$ and $\text{'}$src$2\text{'}$ are the output operand, the first source operand, and the second source operand, respectively.