Find the value of the given expression:
$$40-\{17-12÷(5+9\times 2-17)\}$$

Solve using the BODMAS rule step by step:
1. Inside the small parenthesis: $5+9\times 2-17=5+18-17=23-17=6$
2. Substitute back into the expression: $40-\{17-12÷6\}$
3. Perform division inside the curly braces: $12÷6=2$
4. Simplify inside the curly braces: $17-2=15$
5. Final subtraction: $40-15=25$