diff --git a/.config/dotnet-tools.json b/.config/dotnet-tools.json
index 0fdcde7e13a..6f319030449 100644
--- a/.config/dotnet-tools.json
+++ b/.config/dotnet-tools.json
@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "fantomas": {
-      "version": "5.0.0-beta-005",
+      "version": "5.0.3",
       "commands": [
         "fantomas"
       ]
diff --git a/.fantomasignore b/.fantomasignore
index a3094f05991..fabfd3547e1 100644
--- a/.fantomasignore
+++ b/.fantomasignore
@@ -12,14 +12,79 @@ artifacts/
 
 # Explicitly unformatted implementation files
 
-src/Compiler/Checking/**/*.fs
-src/Compiler/DependencyManager/**/*.fs
-src/Compiler/Facilities/**/*.fs
-src/Compiler/Interactive/**/*.fs
-src/Compiler/Legacy/**/*.fs
-src/Compiler/Optimize/**/*.fs
-src/Compiler/Symbols/**/*.fs
-src/Compiler/TypedTree/**/*.fs
+src/Compiler/Checking/AccessibilityLogic.fs
+src/Compiler/Checking/AttributeChecking.fs
+src/Compiler/Checking/AugmentWithHashCompare.fs
+src/Compiler/Checking/CheckBasics.fs
+src/Compiler/Checking/CheckComputationExpressions.fs
+src/Compiler/Checking/CheckDeclarations.fs
+src/Compiler/Checking/CheckExpressions.fs
+src/Compiler/Checking/CheckFormatStrings.fs
+src/Compiler/Checking/CheckIncrementalClasses.fs
+src/Compiler/Checking/CheckPatterns.fs
+src/Compiler/Checking/ConstraintSolver.fs
+src/Compiler/Checking/FindUnsolved.fs
+src/Compiler/Checking/import.fs
+src/Compiler/Checking/InfoReader.fs
+src/Compiler/Checking/infos.fs
+src/Compiler/Checking/MethodCalls.fs
+src/Compiler/Checking/MethodOverrides.fs
+src/Compiler/Checking/NameResolution.fs
+src/Compiler/Checking/NicePrint.fs
+src/Compiler/Checking/PatternMatchCompilation.fs
+src/Compiler/Checking/PostInferenceChecks.fs
+src/Compiler/Checking/QuotationTranslator.fs
+src/Compiler/Checking/SignatureConformance.fs
+src/Compiler/Checking/TypeHierarchy.fs
+src/Compiler/Checking/TypeRelations.fs
+
+src/Compiler/DependencyManager/AssemblyResolveHandler.fs
+src/Compiler/DependencyManager/DependencyProvider.fs
+src/Compiler/DependencyManager/NativeDllResolveHandler.fs
+
+src/Compiler/Facilities/BuildGraph.fs
+src/Compiler/Facilities/CompilerLocation.fs
+src/Compiler/Facilities/DiagnosticOptions.fs
+src/Compiler/Facilities/DiagnosticResolutionHints.fs
+src/Compiler/Facilities/DiagnosticsLogger.fs
+src/Compiler/Facilities/LanguageFeatures.fs
+src/Compiler/Facilities/Logger.fs
+src/Compiler/Facilities/prim-lexing.fs
+src/Compiler/Facilities/prim-parsing.fs
+src/Compiler/Facilities/ReferenceResolver.fs
+src/Compiler/Facilities/SimulatedMSBuildReferenceResolver.fs
+src/Compiler/Facilities/TextLayoutRender.fs
+
+src/Compiler/Interactive/ControlledExecution.fs
+src/Compiler/Interactive/fsi.fs
+
+src/Compiler/Legacy/LegacyHostedCompilerForTesting.fs
+src/Compiler/Legacy/LegacyMSBuildReferenceResolver.fs
+
+src/Compiler/Optimize/DetupleArgs.fs
+src/Compiler/Optimize/InnerLambdasToTopLevelFuncs.fs
+src/Compiler/Optimize/LowerCalls.fs
+src/Compiler/Optimize/LowerComputedCollections.fs
+src/Compiler/Optimize/LowerLocalMutables.fs
+src/Compiler/Optimize/LowerSequences.fs
+src/Compiler/Optimize/LowerStateMachines.fs
+src/Compiler/Optimize/Optimizer.fs
+
+src/Compiler/Symbols/Exprs.fs
+src/Compiler/Symbols/FSharpDiagnostic.fs
+src/Compiler/Symbols/SymbolHelpers.fs
+src/Compiler/Symbols/SymbolPatterns.fs
+src/Compiler/Symbols/Symbols.fs
+
+src/Compiler/TypedTree/CompilerGlobalState.fs
+src/Compiler/TypedTree/QuotationPickler.fs
+src/Compiler/TypedTree/tainted.fs
+src/Compiler/TypedTree/TcGlobals.fs
+src/Compiler/TypedTree/TypedTree.fs
+src/Compiler/TypedTree/TypedTreeBasics.fs
+src/Compiler/TypedTree/TypedTreeOps.fs
+src/Compiler/TypedTree/TypedTreePickle.fs
+src/Compiler/TypedTree/TypeProviders.fs
 
 # Explicitly unformatted file that needs more care to get it to format well
 
diff --git a/src/Compiler/CodeGen/IlxGen.fs b/src/Compiler/CodeGen/IlxGen.fs
index 829b7e03d20..1c3d18ffcd1 100644
--- a/src/Compiler/CodeGen/IlxGen.fs
+++ b/src/Compiler/CodeGen/IlxGen.fs
@@ -2840,9 +2840,7 @@ let ComputeDebugPointForBinding g bind =
         | DebugPointAtBinding.NoneAtDo, _ -> false, None
         | DebugPointAtBinding.NoneAtLet, _ -> false, None
         // Don't emit debug points for lambdas.
-        | _,
-          (Expr.Lambda _
-          | Expr.TyLambda _) -> false, None
+        | _, (Expr.Lambda _ | Expr.TyLambda _) -> false, None
         | DebugPointAtBinding.Yes m, _ -> false, Some m
 
 //-------------------------------------------------------------------------
@@ -5134,21 +5132,10 @@ and GenAsmCode cenv cgbuf eenv (il, tyargs, args, returnTys, m) sequel =
     // For these we can just generate the argument and change the test (from a brfalse to a brtrue and vice versa)
     | ([ AI_ceq ],
        [ arg1
-         Expr.Const ((Const.Bool false
-                     | Const.SByte 0y
-                     | Const.Int16 0s
-                     | Const.Int32 0
-                     | Const.Int64 0L
-                     | Const.Byte 0uy
-                     | Const.UInt16 0us
-                     | Const.UInt32 0u
-                     | Const.UInt64 0UL),
+         Expr.Const ((Const.Bool false | Const.SByte 0y | Const.Int16 0s | Const.Int32 0 | Const.Int64 0L | Const.Byte 0uy | Const.UInt16 0us | Const.UInt32 0u | Const.UInt64 0UL),
                      _,
                      _) ],
-       CmpThenBrOrContinue (1,
-                            [ I_brcmp ((BI_brfalse
-                                       | BI_brtrue) as bi,
-                                       label1) ]),
+       CmpThenBrOrContinue (1, [ I_brcmp ((BI_brfalse | BI_brtrue) as bi, label1) ]),
        _) ->
 
         let bi =
@@ -7903,9 +7890,7 @@ and GenDecisionTreeTest
             // If so, emit the failure logic, then came back and do the success target, then
             // do any postponed failure target.
             match successTree, failureTree with
-            | TDSuccess _,
-              (TDBind _
-              | TDSwitch _) ->
+            | TDSuccess _, (TDBind _ | TDSwitch _) ->
 
                 // OK, there is more logic in the decision tree on the failure branch
                 let success = CG.GenerateDelayMark cgbuf "testSuccess"
@@ -10641,10 +10626,9 @@ and GenTypeDef cenv mgbuf lazyInitInfo eenv m (tycon: Tycon) =
                     | None -> None
                     | Some memberInfo ->
                         match name, memberInfo.MemberFlags.MemberKind with
-                        | ("Item"
-                          | "op_IndexedLookup"),
-                          (SynMemberKind.PropertyGet
-                          | SynMemberKind.PropertySet) when not (isNil (ArgInfosOfPropertyVal g vref.Deref)) ->
+                        | ("Item" | "op_IndexedLookup"), (SynMemberKind.PropertyGet | SynMemberKind.PropertySet) when
+                            not (isNil (ArgInfosOfPropertyVal g vref.Deref))
+                            ->
                             Some(
                                 mkILCustomAttribute (
                                     g.FindSysILTypeRef "System.Reflection.DefaultMemberAttribute",
diff --git a/src/Compiler/Driver/ParseAndCheckInputs.fs b/src/Compiler/Driver/ParseAndCheckInputs.fs
index db3f30d41b5..3f4ac2f89ee 100644
--- a/src/Compiler/Driver/ParseAndCheckInputs.fs
+++ b/src/Compiler/Driver/ParseAndCheckInputs.fs
@@ -844,10 +844,7 @@ let ProcessMetaCommandsFromInput
             | ParsedHashDirective ("nowarn", ParsedHashDirectiveArguments numbers, m) ->
                 List.fold (fun state d -> nowarnF state (m, d)) state numbers
 
-            | ParsedHashDirective (("reference"
-                                   | "r"),
-                                   ParsedHashDirectiveArguments args,
-                                   m) ->
+            | ParsedHashDirective (("reference" | "r"), ParsedHashDirectiveArguments args, m) ->
                 matchedm <- m
                 ProcessDependencyManagerDirective Directive.Resolution args m state
 
diff --git a/src/Compiler/Service/FSharpCheckerResults.fs b/src/Compiler/Service/FSharpCheckerResults.fs
index 70647f70d59..0abff6d4d04 100644
--- a/src/Compiler/Service/FSharpCheckerResults.fs
+++ b/src/Compiler/Service/FSharpCheckerResults.fs
@@ -247,9 +247,7 @@ type FSharpSymbolUse(denv: DisplayEnv, symbol: FSharpSymbol, inst: TyparInstanti
         // 'seq' in 'seq { ... }' gets colored as keywords
         | Item.Value vref, ItemOccurence.Use when valRefEq denv.g denv.g.seq_vref vref -> true
         // custom builders, custom operations get colored as keywords
-        | (Item.CustomBuilder _
-          | Item.CustomOperation _),
-          ItemOccurence.Use -> true
+        | (Item.CustomBuilder _ | Item.CustomOperation _), ItemOccurence.Use -> true
         | _ -> false
 
     member _.IsFromOpenStatement = itemOcc = ItemOccurence.Open
@@ -2306,14 +2304,8 @@ module internal ParseAndCheckFile =
 
                     matchBraces stackAfterMatch
 
-                | LPAREN
-                  | LBRACE _
-                  | LBRACK
-                  | LBRACE_BAR
-                  | LBRACK_BAR
-                  | LQUOTE _
-                  | LBRACK_LESS as tok,
-                  _ -> matchBraces ((tok, lexbuf.LexemeRange) :: stack)
+                | LPAREN | LBRACE _ | LBRACK | LBRACE_BAR | LBRACK_BAR | LQUOTE _ | LBRACK_LESS as tok, _ ->
+                    matchBraces ((tok, lexbuf.LexemeRange) :: stack)
 
                 // INTERP_STRING_BEGIN_PART corresponds to $"... {" at the start of an interpolated string
                 //
@@ -2322,9 +2314,7 @@ module internal ParseAndCheckFile =
                 //   interpolation expression)
                 //
                 // Either way we start a new potential match at the last character
-                | INTERP_STRING_BEGIN_PART _
-                  | INTERP_STRING_PART _ as tok,
-                  _ ->
+                | INTERP_STRING_BEGIN_PART _ | INTERP_STRING_PART _ as tok, _ ->
                     let m = lexbuf.LexemeRange
 
                     let m2 =
@@ -2332,9 +2322,7 @@ module internal ParseAndCheckFile =
 
                     matchBraces ((tok, m2) :: stack)
 
-                | (EOF _
-                  | LEX_FAILURE _),
-                  _ -> ()
+                | (EOF _ | LEX_FAILURE _), _ -> ()
                 | _ -> matchBraces stack
 
             matchBraces [])
diff --git a/src/Compiler/Service/SemanticClassification.fs b/src/Compiler/Service/SemanticClassification.fs
index 5da02e32094..8fe50e9c241 100644
--- a/src/Compiler/Service/SemanticClassification.fs
+++ b/src/Compiler/Service/SemanticClassification.fs
@@ -212,10 +212,8 @@ module TcResolutionsExtensions =
                     resolutions
                     |> Array.iter (fun cnr ->
                         match cnr.Item, cnr.ItemOccurence, cnr.Range with
-                        | (Item.CustomBuilder _
-                          | Item.CustomOperation _),
-                          ItemOccurence.Use,
-                          m -> add m SemanticClassificationType.ComputationExpression
+                        | (Item.CustomBuilder _ | Item.CustomOperation _), ItemOccurence.Use, m ->
+                            add m SemanticClassificationType.ComputationExpression
 
                         | Item.Value vref, _, m when isValRefMutable g vref -> add m SemanticClassificationType.MutableVar
 
diff --git a/src/Compiler/Service/ServiceLexing.fs b/src/Compiler/Service/ServiceLexing.fs
index 80cfb38cc6c..a772cd707aa 100644
--- a/src/Compiler/Service/ServiceLexing.fs
+++ b/src/Compiler/Service/ServiceLexing.fs
@@ -205,13 +205,9 @@ module internal TokenClassifications =
             // (this isn't entirely correct, but it'll work for now - see bug 3727)
             (FSharpTokenColorKind.Number, FSharpTokenCharKind.Operator, FSharpTokenTriggerClass.None)
 
-        | INFIX_STAR_DIV_MOD_OP ("mod"
-        | "land"
-        | "lor"
-        | "lxor")
-        | INFIX_STAR_STAR_OP ("lsl"
-        | "lsr"
-        | "asr") -> (FSharpTokenColorKind.Keyword, FSharpTokenCharKind.Keyword, FSharpTokenTriggerClass.None)
+        | INFIX_STAR_DIV_MOD_OP ("mod" | "land" | "lor" | "lxor")
+        | INFIX_STAR_STAR_OP ("lsl" | "lsr" | "asr") ->
+            (FSharpTokenColorKind.Keyword, FSharpTokenCharKind.Keyword, FSharpTokenTriggerClass.None)
 
         | LPAREN_STAR_RPAREN
         | DOLLAR
diff --git a/src/Compiler/Service/ServiceParsedInputOps.fs b/src/Compiler/Service/ServiceParsedInputOps.fs
index 7d3c916bc8e..ef194965b34 100644
--- a/src/Compiler/Service/ServiceParsedInputOps.fs
+++ b/src/Compiler/Service/ServiceParsedInputOps.fs
@@ -2037,10 +2037,7 @@ module ParsedInput =
                     result <- Some(oldScope, oldPos, true)
                 | Some (oldScope, oldPos, _), _ ->
                     match kind, oldScope.Kind with
-                    | (Namespace
-                      | NestedModule
-                      | TopModule),
-                      OpenDeclaration
+                    | (Namespace | NestedModule | TopModule), OpenDeclaration
                     | _ when oldPos.Line <= line ->
                         result <-
                             Some(
diff --git a/src/Compiler/TypedTree/QuotationPickler.fsi b/src/Compiler/TypedTree/QuotationPickler.fsi
index 648e9d0acf6..fb7dbd2be5a 100644
--- a/src/Compiler/TypedTree/QuotationPickler.fsi
+++ b/src/Compiler/TypedTree/QuotationPickler.fsi
@@ -2,6 +2,7 @@
 
 /// Code to pickle out quotations in the quotation binary format.
 module internal FSharp.Compiler.QuotationPickler
+
 #nowarn "1178"
 
 type TypeData
diff --git a/src/FSharp.Core/local.fsi b/src/FSharp.Core/local.fsi
index e4d26e76e2b..2af9465beaf 100644
--- a/src/FSharp.Core/local.fsi
+++ b/src/FSharp.Core/local.fsi
@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
 
 namespace Microsoft.FSharp.Core
+
 open Microsoft.FSharp.Core
 
 [<AutoOpen>]
diff --git a/src/FSharp.Core/quotations.fs b/src/FSharp.Core/quotations.fs
index 44c625de5f5..c3c7317e522 100644
--- a/src/FSharp.Core/quotations.fs
+++ b/src/FSharp.Core/quotations.fs
@@ -942,14 +942,8 @@ module Patterns =
             | VarSetOp, _
             | AddressSetOp, _ -> typeof<Unit>
             | AddressOfOp, [ expr ] -> (typeOf expr).MakeByRefType()
-            | (AddressOfOp
-              | QuoteOp _
-              | SequentialOp
-              | TryWithOp
-              | TryFinallyOp
-              | IfThenElseOp
-              | AppOp),
-              _ -> failwith "unreachable"
+            | (AddressOfOp | QuoteOp _ | SequentialOp | TryWithOp | TryFinallyOp | IfThenElseOp | AppOp), _ ->
+                failwith "unreachable"
 
     //--------------------------------------------------------------------------
     // Constructors for building Raw quotations
@@ -2933,8 +2927,7 @@ module DerivedPatterns =
     let (|SpecificCall|_|) templateParameter =
         // Note: precomputation
         match templateParameter with
-        | (Lambdas (_, Call (_, minfo1, _))
-        | Call (_, minfo1, _)) ->
+        | (Lambdas (_, Call (_, minfo1, _)) | Call (_, minfo1, _)) ->
             let isg1 = minfo1.IsGenericMethod
 
             let gmd =
diff --git a/src/FSharp.Core/seqcore.fsi b/src/FSharp.Core/seqcore.fsi
index 03496378232..701a92fc705 100644
--- a/src/FSharp.Core/seqcore.fsi
+++ b/src/FSharp.Core/seqcore.fsi
@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information.
 
 namespace Microsoft.FSharp.Collections
+
 open System
 open System.Collections
 open System.Collections.Generic