Unify/simplify pickles variable names

src/lib/mina_wire_types/pickles/pickles_composition_types.ml

@@ -76,7 +76,7 @@ module Wrap = struct
           { plonk : 'plonk
           ; combined_inner_product : 'fp
           ; b : 'fp
-          ; xi : 'scalar_challenge
+          ; polyscale : 'scalar_challenge
           ; bulletproof_challenges : 'bulletproof_challenges
           ; branch_data : 'branch_data
           }

src/lib/mina_wire_types/pickles/pickles_composition_types.mli

@@ -64,7 +64,7 @@ module Wrap : sig
           { plonk : 'plonk
           ; combined_inner_product : 'fp
           ; b : 'fp
-          ; xi : 'scalar_challenge
+          ; polyscale : 'scalar_challenge
           ; bulletproof_challenges : 'bulletproof_challenges
           ; branch_data : 'branch_data
           }

src/lib/pickles/common.ml

@@ -252,18 +252,18 @@ let ft_comm ~add:( + ) ~scale ~negate
 
 let combined_evaluation (type f)
     (module Impl : Snarky_backendless.Snark_intf.Run with type field = f)
-    ~(xi : Impl.Field.t) (without_degree_bound : _ list) =
+    ~(polyscale : Impl.Field.t) (without_degree_bound : _ list) =
   let open Impl in
   let open Field in
-  let mul_and_add ~(acc : Field.t) ~(xi : Field.t)
+  let mul_and_add ~(acc : Field.t) ~(polyscale : Field.t)
       (fx : (Field.t, Boolean.var) Opt.t) : Field.t =
     match fx with
     | Nothing ->
         acc
     | Just fx ->
-        fx + (xi * acc)
+        fx + (polyscale * acc)
     | Maybe (b, fx) ->
-        Field.if_ b ~then_:(fx + (xi * acc)) ~else_:acc
+        Field.if_ b ~then_:(fx + (polyscale * acc)) ~else_:acc
   in
   with_label __LOC__ (fun () ->
       Pcs_batch.combine_split_evaluations ~mul_and_add
@@ -274,4 +274,4 @@ let combined_evaluation (type f)
               Field.zero
           | Maybe (b, x) ->
               (b :> Field.t) * x )
-        ~xi without_degree_bound )
+        ~polyscale without_degree_bound )

src/lib/pickles/common.mli

@@ -58,7 +58,7 @@ val dlog_pcs_batch :
 
 val combined_evaluation :
      (module Snarky_backendless.Snark_intf.Run with type field = 'f)
-  -> xi:'f Snarky_backendless.Cvar.t
+  -> polyscale:'f Snarky_backendless.Cvar.t
   -> ( 'f Snarky_backendless.Cvar.t
      , 'f Snarky_backendless.Cvar.t Snarky_backendless.Snark_intf.Boolean0.t )
      Pickles_types.Opt.t

src/lib/pickles/composition_types/composition_types.ml

@@ -199,12 +199,12 @@ module Wrap = struct
                 .t =
             { plonk : 'plonk
             ; combined_inner_product : 'fp
-                  (** combined_inner_product = sum_{i < num_evaluation_points} sum_{j < num_polys} r^i xi^j f_j(pt_i) *)
+                  (** combined_inner_product = sum_{i < num_evaluation_points} sum_{j < num_polys} evalscale^i polyscale^j f_j(pt_i) *)
             ; b : 'fp
-                  (** b = challenge_poly plonk.zeta + r * challenge_poly (domain_generrator * plonk.zeta)
+                  (** b = challenge_poly plonk.zeta + evalscale * challenge_poly (domain_generator * plonk.zeta)
                 where challenge_poly(x) = \prod_i (1 + bulletproof_challenges.(i) * x^{2^{k - 1 - i}})
             *)
-            ; xi : 'scalar_challenge
+            ; polyscale : 'scalar_challenge
                   (** The challenge used for combining polynomials *)
             ; bulletproof_challenges : 'bulletproof_challenges
                   (** The challenges from the inner-product argument that was partially verified. *)
@@ -232,7 +232,7 @@ module Wrap = struct
         { plonk : 'plonk
         ; combined_inner_product : 'fp
         ; b : 'fp
-        ; xi : 'scalar_challenge
+        ; polyscale : 'scalar_challenge
         ; bulletproof_challenges : 'bulletproof_challenges
         ; branch_data : 'branch_data
         }
@@ -284,11 +284,11 @@ module Wrap = struct
           { plonk
           ; combined_inner_product
           ; b : 'fp
-          ; xi
+          ; polyscale
           ; bulletproof_challenges
           ; branch_data
           } ~f:_ ~scalar =
-        { xi = scalar xi
+        { polyscale = scalar polyscale
         ; combined_inner_product
         ; b
         ; plonk
@@ -343,7 +343,7 @@ module Wrap = struct
           ({ plonk
            ; combined_inner_product = _
            ; b = _
-           ; xi = _
+           ; polyscale = _
            ; bulletproof_challenges
            ; branch_data
            } :
@@ -776,7 +776,7 @@ module Wrap = struct
       let[@warning "-45"] to_data
           ({ proof_state =
                { deferred_values =
-                   { xi
+                   { polyscale
                    ; combined_inner_product
                    ; b
                    ; branch_data
@@ -811,7 +811,7 @@ module Wrap = struct
           ]
         in
         let challenge = [ beta; gamma ] in
-        let scalar_challenge = [ alpha; zeta; xi ] in
+        let scalar_challenge = [ alpha; zeta; polyscale ] in
         let digest =
           [ sponge_digest_before_evaluations
           ; messages_for_next_wrap_proof
@@ -852,7 +852,7 @@ module Wrap = struct
           fp
         in
         let [ beta; gamma ] = challenge in
-        let [ alpha; zeta; xi ] = scalar_challenge in
+        let [ alpha; zeta; polyscale ] = scalar_challenge in
         let [ sponge_digest_before_evaluations
             ; messages_for_next_wrap_proof
             ; messages_for_next_step_proof
@@ -863,7 +863,7 @@ module Wrap = struct
         let feature_flags = Plonk_types.Features.of_data feature_flags in
         { proof_state =
             { deferred_values =
-                { xi
+                { polyscale
                 ; combined_inner_product
                 ; b
                 ; branch_data
@@ -911,7 +911,8 @@ module Step = struct
       *)
       type 'fq t =
         { b : 'fq
-        ; combined_inner_product : 'fq (* sum_i r^i sum_j xi^j f_j(pt_i) *)
+        ; combined_inner_product : 'fq
+              (* sum_i evalscale^i sum_j polyscale^j f_j(pt_i) *)
         }
       [@@deriving hlist]
     end
@@ -1086,13 +1087,13 @@ module Step = struct
       type ('plonk, 'scalar_challenge, 'fq, 'bulletproof_challenges) t_ =
         { plonk : 'plonk
         ; combined_inner_product : 'fq
-              (** combined_inner_product = sum_{i < num_evaluation_points} sum_{j < num_polys} r^i xi^j f_j(pt_i) *)
-        ; xi : 'scalar_challenge
+              (** combined_inner_product = sum_{i < num_evaluation_points} sum_{j < num_polys} evalscale^i polyscale^j f_j(pt_i) *)
+        ; polyscale : 'scalar_challenge
               (** The challenge used for combining polynomials *)
         ; bulletproof_challenges : 'bulletproof_challenges
               (** The challenges from the inner-product argument that was partially verified. *)
         ; b : 'fq
-              (** b = challenge_poly plonk.zeta + r * challenge_poly (domain_generrator * plonk.zeta)
+              (** b = challenge_poly plonk.zeta + evalscale * challenge_poly (domain_generator * plonk.zeta)
                 where challenge_poly(x) = \prod_i (1 + bulletproof_challenges.(i) * x^{2^{k - 1 - i}})
             *)
         }
@@ -1211,7 +1212,7 @@ module Step = struct
 
         let[@warning "-45"] to_data
             ({ deferred_values =
-                 { xi
+                 { polyscale
                  ; bulletproof_challenges
                  ; b
                  ; combined_inner_product
@@ -1239,7 +1240,7 @@ module Step = struct
             ]
           in
           let challenge = [ beta; gamma ] in
-          let scalar_challenge = [ alpha; zeta; xi ] in
+          let scalar_challenge = [ alpha; zeta; polyscale ] in
           let digest = [ sponge_digest_before_evaluations ] in
           let bool = [ should_finalize ] in
           let open Hlist.HlistId in
@@ -1262,12 +1263,12 @@ module Step = struct
                   ]
               ; Vector.[ sponge_digest_before_evaluations ]
               ; Vector.[ beta; gamma ]
-              ; Vector.[ alpha; zeta; xi ]
+              ; Vector.[ alpha; zeta; polyscale ]
               ; bulletproof_challenges
               ; Vector.[ should_finalize ]
               ] : _ t =
           { deferred_values =
-              { xi
+              { polyscale
               ; bulletproof_challenges
               ; b
               ; combined_inner_product

src/lib/pickles/composition_types/composition_types.mli

@@ -170,12 +170,12 @@ module Wrap : sig
                 .t =
             { plonk : 'plonk
             ; combined_inner_product : 'fp
-                  (** combined_inner_product = sum_{i < num_evaluation_points} sum_{j < num_polys} r^i xi^j f_j(pt_i) *)
+                  (** combined_inner_product = sum_{i < num_evaluation_points} sum_{j < num_polys} evalscale^i polyscale^j f_j(pt_i) *)
             ; b : 'fp
-                  (** b = challenge_poly plonk.zeta + r * challenge_poly (domain_generrator * plonk.zeta)
+                  (** b = challenge_poly plonk.zeta + evalscale * challenge_poly (domain_generator * plonk.zeta)
                 where challenge_poly(x) = \prod_i (1 + bulletproof_challenges.(i) * x^{2^{k - 1 - i}})
             *)
-            ; xi : 'scalar_challenge
+            ; polyscale : 'scalar_challenge
                   (** The challenge used for combining polynomials *)
             ; bulletproof_challenges : 'bulletproof_challenges
                   (** The challenges from the inner-product argument that was partially verified. *)
@@ -208,7 +208,7 @@ module Wrap : sig
         { plonk : 'plonk
         ; combined_inner_product : 'fp
         ; b : 'fp
-        ; xi : 'scalar_challenge
+        ; polyscale : 'scalar_challenge
         ; bulletproof_challenges : 'bulletproof_challenges
         ; branch_data : 'branch_data
         }
@@ -1010,13 +1010,13 @@ module Step : sig
       type ('plonk, 'scalar_challenge, 'fq, 'bulletproof_challenges) t_ =
         { plonk : 'plonk
         ; combined_inner_product : 'fq
-              (** combined_inner_product = sum_{i < num_evaluation_points} sum_{j < num_polys} r^i xi^j f_j(pt_i) *)
-        ; xi : 'scalar_challenge
+              (** combined_inner_product = sum_{i < num_evaluation_points} sum_{j < num_polys} evalscale^i polyscale^j f_j(pt_i) *)
+        ; polyscale : 'scalar_challenge
               (** The challenge used for combining polynomials *)
         ; bulletproof_challenges : 'bulletproof_challenges
               (** The challenges from the inner-product argument that was partially verified. *)
         ; b : 'fq
-              (** b = challenge_poly plonk.zeta + r * challenge_poly (domain_generrator * plonk.zeta)
+              (** b = challenge_poly plonk.zeta + evalscale * challenge_poly (domain_generator * plonk.zeta)
                 where challenge_poly(x) = \prod_i (1 + bulletproof_challenges.(i) * x^{2^{k - 1 - i}})
             *)
         }

src/lib/pickles/pickles.ml

@@ -1486,17 +1486,17 @@ module Make_str (_ : Wire_types.Concrete) = struct
                         ; feature_flags = Plonk_types.Features.none_bool
                         }
                       in
-                      let r = scalar_chal O.u in
-                      let xi = scalar_chal O.v in
+                      let evalscale = scalar_chal O.u in
+                      let polyscale = scalar_chal O.v in
                       let to_field =
                         SC.to_field_constant
                           (module Tick.Field)
                           ~endo:Endo.Wrap_inner_curve.scalar
                       in
                       let module As_field = struct
-                        let r = to_field r
+                        let evalscale = to_field evalscale
 
-                        let xi = to_field xi
+                        let polyscale = to_field polyscale
 
                         let zeta = to_field plonk0.zeta
 
@@ -1584,7 +1584,7 @@ module Make_str (_ : Wire_types.Concrete) = struct
                               (let x1, x2 = x_hat in
                                ([| x1 |], [| x2 |]) )
                           }
-                          ~r ~xi ~zeta ~zetaw
+                          ~evalscale ~polyscale ~zeta ~zetaw
                           ~old_bulletproof_challenges:prev_challenges
                           ~env:tick_env ~domain:tick_domain
                           ~ft_eval1:proof.proof.openings.ft_eval1
@@ -1611,7 +1611,7 @@ module Make_str (_ : Wire_types.Concrete) = struct
                         let b =
                           let open Tick.Field in
                           challenge_polynomial zeta
-                          + (r * challenge_polynomial zetaw)
+                          + (evalscale * challenge_polynomial zetaw)
                         in
                         let overwritten_prechals =
                           Array.map prechals
@@ -1687,7 +1687,7 @@ module Make_str (_ : Wire_types.Concrete) = struct
                       in
                       { proof_state =
                           { deferred_values =
-                              { xi
+                              { polyscale
                               ; b = shift_value b
                               ; bulletproof_challenges =
                                   Vector.of_array_and_length_exn

src/lib/pickles/step.ml

@@ -276,7 +276,7 @@ struct
                  ; combined_inner_product =
                      deferred_values.combined_inner_product
                  ; b = deferred_values.b
-                 ; xi = deferred_values.xi
+                 ; polyscale = deferred_values.polyscale
                  ; bulletproof_challenges =
                      statement.proof_state.deferred_values
                        .bulletproof_challenges
@@ -333,18 +333,18 @@ struct
         ; feature_flags = Plonk_types.Features.none_bool
         }
       in
-      let xi = scalar_chal O.v in
-      let r = scalar_chal O.u in
+      let polyscale = scalar_chal O.v in
+      let evalscale = scalar_chal O.u in
       let sponge_digest_before_evaluations = O.digest_before_evaluations o in
       let to_field =
         SC.to_field_constant
           (module Tock.Field)
           ~endo:Endo.Step_inner_curve.scalar
       in
       let module As_field = struct
-        let r = to_field r
+        let evalscale = to_field evalscale
 
-        let xi = to_field xi
+        let polyscale = to_field polyscale
 
         let zeta = to_field plonk0.zeta
 
@@ -368,7 +368,7 @@ struct
         let open As_field in
         let b =
           let open Tock.Field in
-          challenge_polynomial zeta + (r * challenge_polynomial zetaw)
+          challenge_polynomial zeta + (evalscale * challenge_polynomial zetaw)
         in
         let prechals =
           Vector.of_list_and_length_exn
@@ -480,8 +480,8 @@ struct
               ([| f x_hat |] :: [| ft_eval |] :: a)
           in
           let open Tock.Field in
-          Pcs_batch.combine_split_evaluations ~xi ~init:Fn.id
-            ~mul_and_add:(fun ~acc ~xi fx -> fx + (xi * acc))
+          Pcs_batch.combine_split_evaluations ~polyscale ~init:Fn.id
+            ~mul_and_add:(fun ~acc ~polyscale fx -> fx + (polyscale * acc))
             v
         in
         let ft_eval0 =
@@ -492,7 +492,8 @@ struct
         in
         let open Tock.Field in
         combine ~which_eval:`Fst ~ft_eval:ft_eval0 As_field.zeta
-        + (r * combine ~which_eval:`Snd ~ft_eval:proof.openings.ft_eval1 zetaw)
+        + evalscale
+          * combine ~which_eval:`Snd ~ft_eval:proof.openings.ft_eval1 zetaw
       in
       let chal = Challenge.Constant.of_tock_field in
       let plonk =
@@ -522,7 +523,7 @@ struct
                 ; gamma = chal plonk0.gamma
                 }
             ; combined_inner_product = shifted_value combined_inner_product
-            ; xi
+            ; polyscale
             ; bulletproof_challenges = new_bulletproof_challenges
             ; b = shifted_value b
             }