# Sprint 55 Plan: Logic and Actor Family (Prolog, Erlang, Elixir)

## Context

Logic and actor systems require distinct execution semantics. Prolog does not cover
actor concurrency; Erlang/Elixir need dedicated modeling.

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## Goals

1. Add logic-query semantics model for Prolog
2. Add actor/mailbox/supervision semantics model for Erlang/Elixir
3. Support constrained projections into imperative/typed targets
4. Force review gates where semantics cannot be preserved automatically

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## Steps

### Step 779: Prolog lowering adapter v1 (query/backtracking model) (12 tests)
### Step 780: Erlang lowering adapter v1 (actor/mailbox model) (10 tests)
### Step 781: Elixir lowering adapter v1 (actor + macro surface model) (10 tests)
### Step 782: Logic-to-imperative projection policy set (10 tests)
### Step 783: Actor-to-thread/async projection policy set (10 tests)
### Step 784: Supervision tree preservation packet model (8 tests)
### Step 785: Unmappable semantic blocklist + mandatory review gate (8 tests)
### Step 786: `whetstone_transpile_logic_actor_family` MCP tool (8 tests)
### Step 787: Family acceptance and divergence report (8 tests)
### Step 788: Sprint 55 integration summary + regression (8 tests)

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## Hard Rule

- No automatic Stable-tier projection for actor semantics without explicit
  runtime model equivalence evidence.