# Algebraic loops

Overview of algebraic loops and their affect on THCC simulation.

An algebraic loop is a set of components that form a loop where an output of each component is connected to a direct feedthrough input of the next one.

For such component groups, it is impossible to define a valid output update sequence. The Typhoon HIL compiler cannot currently solve algebraic loops. A model validator, invoked prior to the compilation process, checks the model against algebraic loops and reports an error in case it detects one.

Note: Some models created in previous versions (2023.2
or earlier) of Typhoon HIL Control Center software may report compilation (validation)
errors or warnings due to more strict algorithms for C code validation and algebraic loop
detection. If an algebraic loop error is detected, in most cases it can be fixed by adding
component an Unit Delay to break the loop.