- A mushroom is a kind of fungus
- In the food chain process fungi have the role of decomposer
- Hence, in the food chain process mushrooms have the role of decomposer

- In the food chain process mushrooms have the role of decomposer
- If something has the role of something else then that something is an example of that something else
- Therefore, an example of a decomposer is a mushroom

Hence, an example of a decomposer is a mushroom
Question
Which is an example of a decomposer?

Context
- If something has the role of something else then that something is an example of that something else 
- A mushroom is a kind of fungus 
- In the food chain process fungi have the role of decomposer