Alignment

For a detailed explanation, consult the automatic alignment paper by Lunden et al. 2021. In a nutshell aligned statements are statements that come in the same order, no matter the random choices that the program has taken.

In SMC Schemas

Alignment here refers to the likelihood-update statements weight, logWeight, and observe. Aligned statements are such statements that are not in deterministic code-blocks.

In MCMC Schemas

Alignment here refers to the sample statement assume. Aligned statements are such statements that are not in deterministic code blocks.