In a syntax-directed translation scheme, when the value of an attribute of a node depends on the values of the attributes of its children, it is categorized as either a synthesized attribute or an inherited attribute. Let's break down the definitions and differences between these two types:
1. **Synthesized Attribute**:
- **Definition**: A synthesized attribute is one whose value at a node is determined by the values of attributes at its children and possibly its siblings as well.
- **Example**: In a syntax tree representing arithmetic expressions, the value of an attribute "type" at a non-terminal node representing an expression could be synthesized by combining the types of its children (operands).
2. **Inherited Attribute**:
- **Definition**: An inherited attribute is one whose value at a node is determined by the values of attributes at its parent and possibly its siblings as well.
- **Example**: In a syntax tree for a programming language, the attribute "scope" at a node representing a block of code could be inherited from its parent node representing the surrounding scope.
So, to answer the question, when the value of an attribute of a node is a function of the values of the attributes of its children, it is called a **synthesized attribute** (Option A).
By understanding the distinction between synthesized and inherited attributes, you can better grasp how information is propagated and computed within a syntax-directed translation scheme.
