diff --git a/src/common/CircularArraySARTTraces.jl b/src/common/CircularArraySARTTraces.jl
index f29093a..3fd601b 100644
--- a/src/common/CircularArraySARTTraces.jl
+++ b/src/common/CircularArraySARTTraces.jl
@@ -1,10 +1,10 @@
 export CircularArraySARTTraces
 
 const CircularArraySARTTraces = Traces{
-    SSAART,
+    SS′AA′RT,
     <:Tuple{
-        <:MultiplexTraces{SS,<:Trace{<:CircularArrayBuffer}},
-        <:MultiplexTraces{AA,<:Trace{<:CircularArrayBuffer}},
+        <:MultiplexTraces{SS′,<:Trace{<:CircularArrayBuffer}},
+        <:MultiplexTraces{AA′,<:Trace{<:CircularArrayBuffer}},
         <:Trace{<:CircularArrayBuffer},
         <:Trace{<:CircularArrayBuffer},
     }
@@ -22,8 +22,8 @@ function CircularArraySARTTraces(;
     reward_eltype, reward_size = reward
     terminal_eltype, terminal_size = terminal
 
-    MultiplexTraces{SS}(CircularArrayBuffer{state_eltype}(state_size..., capacity + 1)) +
-    MultiplexTraces{AA}(CircularArrayBuffer{action_eltype}(action_size..., capacity + 1)) +
+    MultiplexTraces{SS′}(CircularArrayBuffer{state_eltype}(state_size..., capacity + 1)) +
+    MultiplexTraces{AA′}(CircularArrayBuffer{action_eltype}(action_size..., capacity + 1)) +
     Traces(
         reward=CircularArrayBuffer{reward_eltype}(reward_size..., capacity),
         terminal=CircularArrayBuffer{terminal_eltype}(terminal_size..., capacity),
diff --git a/src/common/CircularArraySLARTTraces.jl b/src/common/CircularArraySLARTTraces.jl
index dc5e5ec..db9ac03 100644
--- a/src/common/CircularArraySLARTTraces.jl
+++ b/src/common/CircularArraySLARTTraces.jl
@@ -1,11 +1,11 @@
 export CircularArraySLARTTraces
 
 const CircularArraySLARTTraces = Traces{
-    SSLLAART,
+    SS′LL′AA′RT,
     <:Tuple{
-        <:MultiplexTraces{SS,<:Trace{<:CircularArrayBuffer}},
-        <:MultiplexTraces{LL,<:Trace{<:CircularArrayBuffer}},
-        <:MultiplexTraces{AA,<:Trace{<:CircularArrayBuffer}},
+        <:MultiplexTraces{SS′,<:Trace{<:CircularArrayBuffer}},
+        <:MultiplexTraces{LL′,<:Trace{<:CircularArrayBuffer}},
+        <:MultiplexTraces{AA′,<:Trace{<:CircularArrayBuffer}},
         <:Trace{<:CircularArrayBuffer},
         <:Trace{<:CircularArrayBuffer},
     }
@@ -25,9 +25,9 @@ function CircularArraySLARTTraces(;
     reward_eltype, reward_size = reward
     terminal_eltype, terminal_size = terminal
 
-    MultiplexTraces{SS}(CircularArrayBuffer{state_eltype}(state_size..., capacity + 1)) +
-    MultiplexTraces{LL}(CircularArrayBuffer{legal_actions_mask_eltype}(legal_actions_mask_size..., capacity + 1)) +
-    MultiplexTraces{AA}(CircularArrayBuffer{action_eltype}(action_size..., capacity + 1)) +
+    MultiplexTraces{SS′}(CircularArrayBuffer{state_eltype}(state_size..., capacity + 1)) +
+    MultiplexTraces{LL′}(CircularArrayBuffer{legal_actions_mask_eltype}(legal_actions_mask_size..., capacity + 1)) +
+    MultiplexTraces{AA′}(CircularArrayBuffer{action_eltype}(action_size..., capacity + 1)) +
     Traces(
         reward=CircularArrayBuffer{reward_eltype}(reward_size..., capacity),
         terminal=CircularArrayBuffer{terminal_eltype}(terminal_size..., capacity),
diff --git a/src/common/common.jl b/src/common/common.jl
index f4c6fad..78d28b3 100644
--- a/src/common/common.jl
+++ b/src/common/common.jl
@@ -1,15 +1,15 @@
-export SS, LL, AA, RT, SSART, SSAART, SSLLAART
+export SS′, LL′, AA′, RT, SS′ART, SS′AA′RT, SS′L′ART, SS′LL′AA′RT
 
 using CircularArrayBuffers
 
-const SS = (:state, :next_state)
-const LL = (:legal_actions_mask, :next_legal_actions_mask)
-const AA = (:action, :next_action)
+const SS′ = (:state, :next_state)
+const LL′ = (:legal_actions_mask, :next_legal_actions_mask)
+const AA′ = (:action, :next_action)
 const RT = (:reward, :terminal)
-const SSART = (SS..., :action, RT...)
-const SSAART = (SS..., AA..., RT...)
-const SSLART = (SS..., :legal_actions_mask, :action, RT...)
-const SSLLAART = (SS..., LL..., AA..., RT...)
+const SS′ART = (SS′..., :action, RT...)
+const SS′AA′RT = (SS′..., AA′..., RT...)
+const SS′L′ART = (SS′..., :next_legal_actions_mask, :action, RT...)
+const SS′LL′AA′RT = (SS′..., LL′..., AA′..., RT...)
 
 include("sum_tree.jl")
 include("CircularArraySARTTraces.jl")
diff --git a/src/samplers.jl b/src/samplers.jl
index fef23bb..927d06e 100644
--- a/src/samplers.jl
+++ b/src/samplers.jl
@@ -31,7 +31,7 @@ sample(s::BatchSampler{names}, t::AbstractTraces) where {names} = sample(s, t, n
 
 function sample(s::BatchSampler, t::AbstractTraces, names)
     inds = rand(s.rng, 1:length(t), s.batch_size)
-    NamedTuple{names}(t[x][inds] for x in names)
+    NamedTuple{names}(map(x -> t[x][inds], names))
 end
 
 #####
@@ -99,7 +99,7 @@ mutable struct NStepBatchSampler{traces}
     rng::Any
 end
 
-NStepBatchSampler(; kw...) = NStepBatchSampler{SSART}(; kw...)
+NStepBatchSampler(; kw...) = NStepBatchSampler{SS′ART}(; kw...)
 NStepBatchSampler{names}(; n, γ, batch_size=32, stack_size=nothing, rng=Random.GLOBAL_RNG) where {names} = NStepBatchSampler{names}(n, γ, batch_size, stack_size, rng)
 
 function sample(s::NStepBatchSampler{names}, ts) where {names}
@@ -108,7 +108,7 @@ function sample(s::NStepBatchSampler{names}, ts) where {names}
     sample(s, ts, Val(names), inds)
 end
 
-function sample(nbs::NStepBatchSampler, ts, ::Val{SSART}, inds)
+function sample(nbs::NStepBatchSampler, ts, ::Val{SS′ART}, inds)
     if isnothing(nbs.stack_size)
         s = ts[:state][inds]
         s′ = ts[:next_state][inds.+(nbs.n-1)]
@@ -129,11 +129,11 @@ function sample(nbs::NStepBatchSampler, ts, ::Val{SSART}, inds)
         foldr(((rr, tt), init) -> rr + nbs.γ * init * (1 - tt), zip(r⃗, t⃗); init=0.0f0)
     end
 
-    NamedTuple{SSART}((s, s′, a, r, t))
+    NamedTuple{SS′ART}((s, s′, a, r, t))
 end
 
-function sample(s::NStepBatchSampler, ts, ::Val{SSLART}, inds)
+function sample(s::NStepBatchSampler, ts, ::Val{SS′L′ART}, inds)
     s, s′, a, r, t = sample(s, ts, Val(SSART), inds)
-    l = consecutive_view(ts[:legal_actions_mask], inds)
+    l = consecutive_view(ts[:next_legal_actions_mask], inds)
     NamedTuple{SSLART}((s, s′, l, a, r, t))
 end
\ No newline at end of file
diff --git a/test/samplers.jl b/test/samplers.jl
index b6ac3b6..8f43fa5 100644
--- a/test/samplers.jl
+++ b/test/samplers.jl
@@ -106,7 +106,7 @@ end
     @test size(xs2.terminal) == (batch_size,)
 
     inds = [3, 5, 7]
-    xs3 = RLTrajectories.sample(s1, t2, Val(SSART), inds)
+    xs3 = RLTrajectories.sample(s1, t2, Val(SS′ART), inds)
 
     @test xs3.state == cat(
         (