<program><Assignment><lhs>x</lhs><Expr><value>1</value></Expr> 
</Assignment> 
<Assignment><lhs>y</lhs><Expr><value>2</value></Expr> 
</Assignment> 
<Assignment><lhs>z</lhs><Expr><op>+</op><Expr>x</Expr> 
<Expr><op>*</op><Expr>y</Expr> 
<Expr><value>2</value></Expr> 
</Expr> 
</Expr> 
</Assignment> 
</program>