How resistance and propagation delay related each other in TTL logic family?

In TTL (Transistor-Transistor Logic) circuits, resistance and propagation delay are inversely related. Higher resistance in the circuit can lead to increased propagation delay, as it affects the charging and discharging times of capacitive loads. This delay is primarily due to the time it takes for the output to transition from one state to another, which is influenced by the RC time constant (where R is resistance and C is capacitance). Thus, optimizing resistance is crucial for improving speed in TTL logic applications.