Free Flat
Abstract
Tensor exactness for the concrete cells used in solidification. The proof uses flat free modules in presheaves and left exact sheafification; it does not assume enough projectives in light condensed abelian groups.
Theorem 1.1 (tensor Free preserves Finite Limits).
Lean statement: D5/S3/HomologicalAlgebra/Solid/FreeFlat.tensorFree_preservesFiniteLimits
Proof. Machine-checked in Lean as D5/S3/HomologicalAlgebra/Solid/FreeFlat.tensorFree_preservesFiniteLimits (✓ std3). ∎
Source. Repository-derived.
Commentary.
Free light condensed abelian groups are flat, including free groups on arbitrary light condensed sets.
Theorem 1.2 (tensor P preserves Finite Limits).
Lean statement: D5/S3/HomologicalAlgebra/Solid/FreeFlat.tensorP_preservesFiniteLimits
Proof. Machine-checked in Lean as D5/S3/HomologicalAlgebra/Solid/FreeFlat.tensorP_preservesFiniteLimits (✓ std3). ∎
Source. Repository-derived.
Commentary.
Tensoring with the protected P is exact. This is a tensor-flatness statement, separate from the protected internal-projectivity instance.
References
- Truth anchor:
D5/S3/HomologicalAlgebra/Solid/FreeFlat.tensorFree_preservesFiniteLimits - Truth anchor:
D5/S3/HomologicalAlgebra/Solid/FreeFlat.tensorP_preservesFiniteLimits - Dependency: D5/S3/HomologicalAlgebra/Solid/Colimits
- Dependency: D5/S3/HomologicalAlgebra/Solid/DerivedAdjunction