Time-Based Signals vs. Event Sequences

• Event sequences:
  • x: Naturals₀ ® Symbols
• Discrete-time signals:
  • x: Naturals₀ ® Reals^K
  • x: Integers ® Reals^K
• Continuous-time signals:
  • x: Reals+ ® Reals^K
  • x: Reals ® Reals^K

The difference between event sequences and discrete-time signals is largely one of interpretation: what is meant by the index in the domain? Time or just ordering? Also, time-based signals more commonly have values in Reals^K for some natural number K.

Hybrid systems combine time-based signals with event sequences.