Adding note about the independent variable restriction. Cf #1074.

Author: lamorton

src/systems/control/controlsystem.jl

@@ -52,11 +52,11 @@ struct ControlSystem <: AbstractControlSystem
     eqs::Vector{Equation}
     """Independent variable."""
     iv::Sym
-    """Dependent (state) variables."""
+    """Dependent (state) variables. Must not contain the independent variable."""
     states::Vector
     """Control variables."""
     controls::Vector
-    """Parameter variables."""
+    """Parameter variables. Must not contain the independent variable."""
     ps::Vector
     observed::Vector{Equation}
     """

src/systems/diffeqs/odesystem.jl

@@ -27,9 +27,9 @@ struct ODESystem <: AbstractODESystem
     eqs::Vector{Equation}
     """Independent variable."""
     iv::Sym
-    """Dependent (state) variables."""
+    """Dependent (state) variables. Must not contain the independent variable."""
     states::Vector
-    """Parameter variables."""
+    """Parameter variables. Must not contain the independent variable."""
     ps::Vector
     observed::Vector{Equation}
     """

src/systems/diffeqs/sdesystem.jl

@@ -33,9 +33,9 @@ struct SDESystem <: AbstractODESystem
     noiseeqs::AbstractArray
     """Independent variable."""
     iv::Sym
-    """Dependent (state) variables."""
+    """Dependent (state) variables. Must not contain the independent variable."""
     states::Vector
-    """Parameter variables."""
+    """Parameter variables. Must not contain the independent variable."""
     ps::Vector
     observed::Vector
     """

src/systems/discrete_system/discrete_system.jl

@@ -26,9 +26,9 @@ struct DiscreteSystem <: AbstractSystem
     eqs::Vector{Equation}
     """Independent variable."""
     iv::Sym
-    """Dependent (state) variables."""
+    """Dependent (state) variables. Must not contain the independent variable."""
     states::Vector
-    """Parameter variables."""
+    """Parameter variables. Must not contain the independent variable."""
     ps::Vector
     observed::Vector{Equation}
     """

src/systems/jumps/jumpsystem.jl

@@ -33,9 +33,9 @@ struct JumpSystem{U <: ArrayPartition} <: AbstractSystem
     eqs::U
     """The independent variable, usually time."""
     iv::Any
-    """The dependent variables, representing the state of the system."""
+    """The dependent variables, representing the state of the system.  Must not contain the independent variable."""
     states::Vector
-    """The parameters of the system."""
+    """The parameters of the system. Must not contain the independent variable."""
     ps::Vector
     observed::Vector{Equation}
     """The name of the system. . These are required to have unique names."""

src/systems/reaction/reactionsystem.jl

@@ -140,9 +140,9 @@ struct ReactionSystem <: AbstractSystem
     eqs::Vector{Reaction}
     """Independent variable (usually time)."""
     iv::Any
-    """Dependent (state) variables representing amount of each species."""
+    """Dependent (state) variables representing amount of each species. Must not contain the independent variable."""
     states::Vector
-    """Parameter variables."""
+    """Parameter variables. Must not contain the independent variable."""
     ps::Vector
     observed::Vector{Equation}
     """The name of the system"""