During the design of asynchronous sequential circuits, it is more convenient to name the state by letters this type of table is known as

The type of table you're referring to, where states in asynchronous sequential circuits are named by letters (typically using identifiers like A, B, C, etc.), is known as a State Table or State Transition Table.

A state table typically consists of:

1. Current State: The state of the system at a given time, represented by letters.
2. Inputs: The different inputs that can affect the state transitions.
3. Next State: The resulting state after the current state and inputs are considered.
4. Outputs: Sometimes, the outputs corresponding to each state or state transition are also included.

Using letters to represent states simplifies the analysis and design of the circuit, making it easier to visualize and implement the transitions between different states based on inputs. This is particularly useful in the design of digital circuits, finite state machines, and other related systems.