Mind · Reasoning
BackwardChain
Goal-driven reasoning from target to preconditions
Definition
Mechanism
Goal-First Decomposition: Start from desired end-state, recursively identify prerequisites. For each prerequisite, ask "what must be true for this to hold?" until reaching known facts or actionable steps. Execution order is reverse of discovery order. A goal-directed form of Deduction — derives required antecedents from the desired consequent. Structures the ChainOfThought in reverse chronological order, linking the desired future state to present preconditions.
Preconditions
- Goal state clearly defined.
- Domain has prerequisite structure.
- Knowledge base queryable.
Postconditions
- Execution plan produced OR goal proven unachievable.
- Plan steps in executable order.
- All prerequisites satisfied.
Invariants
- Causal Sufficiency: Step(T) must be sufficient condition for Step(T+1)
- Goal Anchoring: Chain must start at DesiredEndState
- Leaf nodes must be actionable or known-true.
Risks
Failure modes
Infinite Regression
The precondition chain never terminates because base facts are missing.
Relationships
Builds on
References
Infrastructure
Sequential data container (linked list)
Step-by-step reasoning (Macro for Think(Chain))
General to specific logic
Infrastructure
An ordered sequence of steps to achieve a goal
Nothing in this library builds on this pattern yet.
Reference