--- a/src/BoundaryConditions/sat.jl	Mon Dec 25 19:23:49 2023 +0100
+++ b/src/BoundaryConditions/sat.jl	Mon Dec 25 19:24:08 2023 +0100
@@ -1,9 +1,11 @@
 """
     sat_tensors(op, grid, bc::BoundaryCondition, params...)
 
-Returns the functions `closure(u)` and `penalty(g)` used to construct a SAT for the
-`LazyTensor` operator `op` on `grid` associated with the boundary condition `bc`,
-where g is the discretized data of `bc`.
+The tensor and boundary operator used to construct a simultaneous-approximation-term
+for imposing `bc` related to `op`.
+
+For `sat_op, L  = sat_tensors(...)` then `SAT = sat_op*(L*u - g)`  where `g` 
+is the boundary data.
 """
 function sat_tensors end
 
@@ -11,12 +13,10 @@
 """
     sat(op, grid, bc::BoundaryCondition, params...)
 
-Simultaneous-Approximation-Term for a general `BoundaryCondition` `bc` to `LazyTensor` `op`. 
-The function returns a function `f`, where f(t,u)` returns a `LazyTensorApplication`
-weakly imposing the boundary condition at time `t`, when added to `op*u`.
+Simultaneous-Approximation-Term for a general `bc` to `op`. 
+Returns a function `SAT(u,g)` weakly imposing `bc` when added to `op*u`.
 
-`op` must implement the function `sat_tensors`. `f` is then constructed as 
-`f(t,u) = closure(u) + `penalty(g(t))`.
+`op` must implement the function `sat_tensors`.
 """
 function sat(op, grid, bc::BoundaryCondition, params...)
     sat_op, L = sat_tensors(op, grid, bc, params...)