diff --git a/implementations/javascript/packages/schema/src/compiler/genconverter.ts b/implementations/javascript/packages/schema/src/compiler/genconverter.ts
index df9a8c0..320ccb5 100644
--- a/implementations/javascript/packages/schema/src/compiler/genconverter.ts
+++ b/implementations/javascript/packages/schema/src/compiler/genconverter.ts
@@ -13,7 +13,7 @@ export function converterForDefinition(
 {
     switch (p._variant) {
         case 'or': {
-            const alts = [p.pattern, ... p.patterns];
+            const alts = [p.pattern0, p.pattern1, ... p.patternN];
             function loop(i: number): Item[] {
                 ctx.variantName = alts[i].variantLabel;
                 return [... converterForPattern(ctx, alts[i].pattern, src, dest),
@@ -24,7 +24,7 @@ export function converterForDefinition(
             return loop(0);
         }
         case 'and': {
-            const pcs = [p.pattern, ... p.patterns];
+            const pcs = [p.pattern0, p.pattern1, ... p.patternN];
             function loop(i: number): Item[] {
                 return (i < pcs.length)
                     ? converterFor(ctx, pcs[i], src, () => loop(i + 1))
diff --git a/implementations/javascript/packages/schema/src/compiler/gentype.ts b/implementations/javascript/packages/schema/src/compiler/gentype.ts
index a8ffa67..69ad8db 100644
--- a/implementations/javascript/packages/schema/src/compiler/gentype.ts
+++ b/implementations/javascript/packages/schema/src/compiler/gentype.ts
@@ -7,10 +7,10 @@ export function typeForDefinition(mod: ModuleContext, d: M.Definition): Type {
     switch (d._variant) {
         case 'or':
             return Type.union(
-                new Map([d.pattern, ... d.patterns].map(a =>
+                new Map([d.pattern0, d.pattern1, ... d.patternN].map(a =>
                     [a.variantLabel, typeFor(mod, a.pattern)])));
         case 'and':
-            return typeForIntersection(mod, [d.pattern, ... d.patterns]);
+            return typeForIntersection(mod, [d.pattern0, d.pattern1, ... d.patternN]);
         case 'Pattern':
             return typeFor(mod, d.value);
     }
diff --git a/implementations/javascript/packages/schema/src/compiler/genunconverter.ts b/implementations/javascript/packages/schema/src/compiler/genunconverter.ts
index 332db2f..f6106f7 100644
--- a/implementations/javascript/packages/schema/src/compiler/genunconverter.ts
+++ b/implementations/javascript/packages/schema/src/compiler/genunconverter.ts
@@ -14,14 +14,14 @@ export function unconverterForDefinition(
     switch (def._variant) {
         case 'or':
             return [seq(`switch (${src}._variant) `, block(
-                ... [def.pattern, ... def.patterns].map(p =>
+                ... [def.pattern0, def.pattern1, ... def.patternN].map(p =>
                     seq(`case `, JSON.stringify(p.variantLabel), `: `, ctx.block(() => {
                         const hasValueField = p.pattern._variant === 'SimplePattern';
                         return [seq(`return `, unconverterForPattern(
                             ctx, name, p.pattern, hasValueField ? `${src}.value` : src))];
                     })))))];
         case 'and': {
-            const ps = [def.pattern , ... def.patterns];
+            const ps = [def.pattern0, def.pattern1, ... def.patternN];
             const t = typeForIntersection(ctx.mod, ps);
             const errs: [string, InsufficientInformationError][] = [];
             const cs = ps.flatMap(p => {
diff --git a/implementations/javascript/packages/schema/src/gen/schema.ts b/implementations/javascript/packages/schema/src/gen/schema.ts
index fc9585b..2ff8905 100644
--- a/implementations/javascript/packages/schema/src/gen/schema.ts
+++ b/implementations/javascript/packages/schema/src/gen/schema.ts
@@ -52,10 +52,16 @@ export type Definitions = _.KeyedDictionary<symbol, Definition, _embedded>;
 export type Definition = (
     {
         "_variant": "or",
-        "pattern": NamedAlternative,
-        "patterns": Array<NamedAlternative>
+        "pattern0": NamedAlternative,
+        "pattern1": NamedAlternative,
+        "patternN": Array<NamedAlternative>
+    } |
+    {
+        "_variant": "and",
+        "pattern0": NamedPattern,
+        "pattern1": NamedPattern,
+        "patternN": Array<NamedPattern>
     } |
-    {"_variant": "and", "pattern": NamedPattern, "patterns": Array<NamedPattern>} |
     {"_variant": "Pattern", "value": Pattern}
 );
 
@@ -137,9 +143,29 @@ export function Definitions(value: _.KeyedDictionary<symbol, Definition, _embedd
 
 export namespace Definition {
     export function or(
-        {pattern, patterns}: {pattern: NamedAlternative, patterns: Array<NamedAlternative>}
-    ): Definition {return {"_variant": "or", "pattern": pattern, "patterns": patterns};};
-    export function and({pattern, patterns}: {pattern: NamedPattern, patterns: Array<NamedPattern>}): Definition {return {"_variant": "and", "pattern": pattern, "patterns": patterns};};
+        {pattern0, pattern1, patternN}: {
+            pattern0: NamedAlternative,
+            pattern1: NamedAlternative,
+            patternN: Array<NamedAlternative>
+        }
+    ): Definition {
+        return {
+            "_variant": "or",
+            "pattern0": pattern0,
+            "pattern1": pattern1,
+            "patternN": patternN
+        };
+    };
+    export function and(
+        {pattern0, pattern1, patternN}: {pattern0: NamedPattern, pattern1: NamedPattern, patternN: Array<NamedPattern>}
+    ): Definition {
+        return {
+            "_variant": "and",
+            "pattern0": pattern0,
+            "pattern1": pattern1,
+            "patternN": patternN
+        };
+    };
     export function Pattern(value: Pattern): Definition {return {"_variant": "Pattern", "value": value};};
 }
 
@@ -384,23 +410,29 @@ export function toDefinition(v: _val): undefined | Definition {
         let _tmp0: (null) | undefined;
         _tmp0 = _.is(v.label, $or) ? null : void 0;
         if (_tmp0 !== void 0) {
-            if (_.Array.isArray(v[0]) && v[0].length >= 1) {
+            if (_.Array.isArray(v[0]) && v[0].length >= 2) {
                 let _tmp1: (NamedAlternative) | undefined;
                 _tmp1 = toNamedAlternative(v[0][0]);
                 if (_tmp1 !== void 0) {
-                    let _tmp2: (Array<_val>) | undefined;
-                    let _tmp3: (Array<NamedAlternative>) | undefined;
-                    _tmp2 = v[0].slice(1);
-                    {
-                        _tmp3 = [];
-                        for (const _tmp4 of _tmp2) {
-                            let _tmp5: (NamedAlternative) | undefined;
-                            _tmp5 = toNamedAlternative(_tmp4);
-                            if (_tmp5 !== void 0) {_tmp3.push(_tmp5); continue;};
-                            _tmp3 = void 0;
-                            break;
+                    let _tmp2: (NamedAlternative) | undefined;
+                    _tmp2 = toNamedAlternative(v[0][1]);
+                    if (_tmp2 !== void 0) {
+                        let _tmp3: (Array<_val>) | undefined;
+                        let _tmp4: (Array<NamedAlternative>) | undefined;
+                        _tmp3 = v[0].slice(2);
+                        {
+                            _tmp4 = [];
+                            for (const _tmp5 of _tmp3) {
+                                let _tmp6: (NamedAlternative) | undefined;
+                                _tmp6 = toNamedAlternative(_tmp5);
+                                if (_tmp6 !== void 0) {_tmp4.push(_tmp6); continue;};
+                                _tmp4 = void 0;
+                                break;
+                            };
+                            if (_tmp4 !== void 0) {
+                                result = {"_variant": "or", "pattern0": _tmp1, "pattern1": _tmp2, "patternN": _tmp4};
+                            };
                         };
-                        if (_tmp3 !== void 0) {result = {"_variant": "or", "pattern": _tmp1, "patterns": _tmp3};};
                     };
                 };
             };
@@ -408,35 +440,41 @@ export function toDefinition(v: _val): undefined | Definition {
     };
     if (result === void 0) {
         if (_.Record.isRecord<_val, _.Tuple<_val>, _embedded>(v)) {
-            let _tmp6: (null) | undefined;
-            _tmp6 = _.is(v.label, $and) ? null : void 0;
-            if (_tmp6 !== void 0) {
-                if (_.Array.isArray(v[0]) && v[0].length >= 1) {
-                    let _tmp7: (NamedPattern) | undefined;
-                    _tmp7 = toNamedPattern(v[0][0]);
-                    if (_tmp7 !== void 0) {
-                        let _tmp8: (Array<_val>) | undefined;
-                        let _tmp9: (Array<NamedPattern>) | undefined;
-                        _tmp8 = v[0].slice(1);
-                        {
-                            _tmp9 = [];
-                            for (const _tmp10 of _tmp8) {
-                                let _tmp11: (NamedPattern) | undefined;
-                                _tmp11 = toNamedPattern(_tmp10);
-                                if (_tmp11 !== void 0) {_tmp9.push(_tmp11); continue;};
-                                _tmp9 = void 0;
-                                break;
+            let _tmp7: (null) | undefined;
+            _tmp7 = _.is(v.label, $and) ? null : void 0;
+            if (_tmp7 !== void 0) {
+                if (_.Array.isArray(v[0]) && v[0].length >= 2) {
+                    let _tmp8: (NamedPattern) | undefined;
+                    _tmp8 = toNamedPattern(v[0][0]);
+                    if (_tmp8 !== void 0) {
+                        let _tmp9: (NamedPattern) | undefined;
+                        _tmp9 = toNamedPattern(v[0][1]);
+                        if (_tmp9 !== void 0) {
+                            let _tmp10: (Array<_val>) | undefined;
+                            let _tmp11: (Array<NamedPattern>) | undefined;
+                            _tmp10 = v[0].slice(2);
+                            {
+                                _tmp11 = [];
+                                for (const _tmp12 of _tmp10) {
+                                    let _tmp13: (NamedPattern) | undefined;
+                                    _tmp13 = toNamedPattern(_tmp12);
+                                    if (_tmp13 !== void 0) {_tmp11.push(_tmp13); continue;};
+                                    _tmp11 = void 0;
+                                    break;
+                                };
+                                if (_tmp11 !== void 0) {
+                                    result = {"_variant": "and", "pattern0": _tmp8, "pattern1": _tmp9, "patternN": _tmp11};
+                                };
                             };
-                            if (_tmp9 !== void 0) {result = {"_variant": "and", "pattern": _tmp7, "patterns": _tmp9};};
                         };
                     };
                 };
             };
         };
         if (result === void 0) {
-            let _tmp12: (Pattern) | undefined;
-            _tmp12 = toPattern(v);
-            if (_tmp12 !== void 0) {result = {"_variant": "Pattern", "value": _tmp12};};
+            let _tmp14: (Pattern) | undefined;
+            _tmp14 = toPattern(v);
+            if (_tmp14 !== void 0) {result = {"_variant": "Pattern", "value": _tmp14};};
         };
     };
     return result;
@@ -449,8 +487,9 @@ export function fromDefinition(_v: Definition): _val {
                 $or,
                 [
                     [
-                        fromNamedAlternative(_v["pattern"]),
-                        ... _v["patterns"].map(v => fromNamedAlternative(v))
+                        fromNamedAlternative(_v["pattern0"]),
+                        fromNamedAlternative(_v["pattern1"]),
+                        ... _v["patternN"].map(v => fromNamedAlternative(v))
                     ]
                 ]
             );
@@ -460,8 +499,9 @@ export function fromDefinition(_v: Definition): _val {
                 $and,
                 [
                     [
-                        fromNamedPattern(_v["pattern"]),
-                        ... _v["patterns"].map(v => fromNamedPattern(v))
+                        fromNamedPattern(_v["pattern0"]),
+                        fromNamedPattern(_v["pattern1"]),
+                        ... _v["patternN"].map(v => fromNamedPattern(v))
                     ]
                 ]
             );
diff --git a/implementations/javascript/packages/schema/src/reader.ts b/implementations/javascript/packages/schema/src/reader.ts
index fcefdf6..a040769 100644
--- a/implementations/javascript/packages/schema/src/reader.ts
+++ b/implementations/javascript/packages/schema/src/reader.ts
@@ -183,15 +183,17 @@ function parseDefinition(name: symbol, pos: Position | null, body: Array<Input>)
 
     if (andPieces.length > 1) {
         return M.Definition.and({
-            pattern: patternName(andPieces[0]),
-            patterns: andPieces.slice(1).map(patternName),
+            pattern0: patternName(andPieces[0]),
+            pattern1: patternName(andPieces[1]),
+            patternN: andPieces.slice(2).map(patternName),
         });
     }
 
     if (orPieces.length > 1) {
         return M.Definition.or({
-            pattern: alternativeName(orPieces[0]),
-            patterns: orPieces.slice(1).map(alternativeName),
+            pattern0: alternativeName(orPieces[0]),
+            pattern1: alternativeName(orPieces[1]),
+            patternN: orPieces.slice(2).map(alternativeName),
         });
     }
 
diff --git a/schema/schema.bin b/schema/schema.bin
index 2c1b1df..07d59f6 100644
--- a/schema/schema.bin
+++ b/schema/schema.bin
@@ -3,6 +3,6 @@ ModulePath
 ModulePath„´łrefµ„łSchema„„łPattern´łorµµ±
SimplePattern´łrefµ„ł
SimplePattern„„µ±CompoundPattern´łrefµ„łCompoundPattern„„„„łVersion´łlit‘„łAtomKind´łorµµ±Boolean´łlitłBoolean„„µ±Float´łlitłFloat„„µ±Double´łlitłDouble„„µ±
SignedInteger´łlitł
SignedInteger„„µ±String´łlitłString„„µ±
 ByteString´łlitł
 ByteString„„µ±Symbol´łlitłSymbol„„„„ł
-Definition´łorµµ±or´łrec´łlitłor„´łtupleµ´łtuple*µ´łnamedłpattern´łrefµ„łNamedAlternative„„„´łnamedłpatterns´łrefµ„łNamedAlternative„„„„„„„µ±and´łrec´łlitłand„´łtupleµ´łtuple*µ´łnamedłpattern´łrefµ„łNamedPattern„„„´łnamedłpatterns´łrefµ„łNamedPattern„„„„„„„µ±Pattern´łrefµ„łPattern„„„„ł
+Definition´łorµµ±or´łrec´łlitłor„´łtupleµ´łtuple*µ´łnamedłpattern0´łrefµ„łNamedAlternative„„´łnamedłpattern1´łrefµ„łNamedAlternative„„„´łnamedłpatternN´łrefµ„łNamedAlternative„„„„„„„µ±and´łrec´łlitłand„´łtupleµ´łtuple*µ´łnamedłpattern0´łrefµ„łNamedPattern„„´łnamedłpattern1´łrefµ„łNamedPattern„„„´łnamedłpatternN´łrefµ„łNamedPattern„„„„„„„µ±Pattern´łrefµ„łPattern„„„„ł
 ModulePath´łtuple*µ„´łatomłSymbol„„łDefinitions´łdictof´łatomłSymbol„´łrefµ„ł
 Definition„„łNamedPattern´łorµµ±named´łrefµ„łNamedSimplePattern_„„µ±	anonymous´łrefµ„łPattern„„„„ł
SimplePattern´łorµµ±any´łlitłany„„µ±atom´łrec´łlitłatom„´łtupleµ´łnamedłatomKind´łrefµ„łAtomKind„„„„„„µ±embedded´łrec´łlitłembedded„´łtupleµ„„„„µ±lit´łrec´łlitłlit„´łtupleµ´łnamedłvaluełany„„„„„µ±Ref´łrefµ„łRef„„„„łCompoundPattern´łorµµ±rec´łrec´łlitłrec„´łtupleµ´łnamedłlabel´łrefµ„łNamedPattern„„´łnamedłfields´łrefµ„łNamedPattern„„„„„„µ±tuple´łrec´łlitłtuple„´łtupleµ´łtuple*µ„´łnamedłpatterns´łrefµ„łNamedPattern„„„„„„„µ±tuple*´łrec´łlitłtuple*„´łtupleµ´łtuple*µ„´łnamedłfixed´łrefµ„łNamedPattern„„„´łnamedłvariable´łrefµ„łNamedSimplePattern„„„„„„µ±setof´łrec´łlitłsetof„´łtupleµ´łnamedłpattern´łrefµ„ł
SimplePattern„„„„„„µ±dictof´łrec´łlitłdictof„´łtupleµ´łnamedłkey´łrefµ„ł
SimplePattern„„´łnamedłvalue´łrefµ„ł
SimplePattern„„„„„„µ±dict´łrec´łlitłdict„´łtupleµ´łnamedłentries´łrefµ„łDictionaryEntries„„„„„„„„łEmbeddedTypeName´łorµµ±Ref´łrefµ„łRef„„µ±false´łlit€„„„„łNamedAlternative´łtupleµ´łnamedłvariantLabel´łatomłString„„´łnamedłpattern´łrefµ„łPattern„„„„łDictionaryEntries´łdictofłany´łrefµ„łNamedSimplePattern„„łNamedSimplePattern´łorµµ±named´łrefµ„łNamedSimplePattern_„„µ±	anonymous´łrefµ„ł
SimplePattern„„„„łNamedSimplePattern_´łrec´łlitłnamed„´łtupleµ´łnamedłname´łatomłSymbol„„´łnamedłpattern´łrefµ„ł
SimplePattern„„„„„„łembeddedType€„„
\ No newline at end of file
diff --git a/schema/schema.prs b/schema/schema.prs
index 6e4f0b9..9f20584 100644
--- a/schema/schema.prs
+++ b/schema/schema.prs
@@ -23,10 +23,10 @@ Definitions = { symbol: Definition ...:... }.
 
 Definition =
   ; Pattern / Pattern / ...
-  / <or [@pattern NamedAlternative @patterns NamedAlternative ...]>
+  / <or [@pattern0 NamedAlternative @pattern1 NamedAlternative @patternN NamedAlternative ...]>
 
   ; Pattern & Pattern & ...
-  / <and [@pattern NamedPattern @patterns NamedPattern ...]>
+  / <and [@pattern0 NamedPattern @pattern1 NamedPattern @patternN NamedPattern ...]>
 
   ; Pattern
   / Pattern