diff --git a/selfhost/cmd/w6c/main.combined.ww b/selfhost/cmd/w6c/main.combined.ww
index 9214b8ed..efe13f8d 100644
--- a/selfhost/cmd/w6c/main.combined.ww
+++ b/selfhost/cmd/w6c/main.combined.ww
@@ -8160,9 +8160,120 @@ fn tinfofornode(c: *checker, n: *node) *tinfo = {
 	return r;
 };
 
+// unifyarith — usual-arithmetic-conversion analogue at the AST-tnode
+// layer. Mirrors cstage cmd/wcc/check.c:580-596 `unify_arith`. The
+// trailing typeeq fallback covers same-typed operands; mismatched typed
+// pairs silently return ltn (cstage flags the same shape — wwstage's
+// checker stays silent here per existing discipline).
+fn unifyarith(c: *checker, ltn: *node, rtn: *node) *node = {
+	let lu: bool = isuntypedint(ltn) || isuntypedfloat(ltn);
+	let ru: bool = isuntypedint(rtn) || isuntypedfloat(rtn);
+	if (lu && ru) {
+		if (isuntypedfloat(ltn) || isuntypedfloat(rtn)) {
+			return mktname(c, "untyped_float");
+		};
+		return mktname(c, "untyped_int");
+	};
+	let conf: bool = false;
+	if (lu) {
+		if (isassignable(c, rtn, ltn, &conf)) { return rtn; };
+	};
+	if (ru) {
+		if (isassignable(c, ltn, rtn, &conf)) { return ltn; };
+	};
+	if (typeeqast(ltn, rtn)) { return ltn; };
+	return ltn;
+};
+
+// binoptype — derive the result tnode of an N_BIN operator expression.
+// Mirrors cstage cmd/wcc/check.c:598-640 `cbinop`. Operates on tnodes
+// returned by exprtype; ptr arithmetic / bitwise / shifts / comparisons /
+// logicals all reflect cstage's rules. Type-mismatch diagnostics are
+// elided here (cstage gates the same shape).
+fn binoptype(c: *checker, e: *node) *node = {
+	let op: tkind = e.op;
+	let ltn: *node = exprtype(c, e.lhs, nil);
+	let rtn: *node = exprtype(c, e.rhs, nil);
+	if (op == tkind.TK_PLUS || op == tkind.TK_MINUS) {
+		if (ltn != nil && ltn.kind == nkind.N_TPTR && isinttypeast(rtn)) {
+			return ltn;
+		};
+	};
+	if (op == tkind.TK_PLUS) {
+		if (isinttypeast(ltn) && rtn != nil && rtn.kind == nkind.N_TPTR) {
+			return rtn;
+		};
+	};
+	if (op == tkind.TK_MINUS) {
+		if (ltn != nil && rtn != nil
+		    && ltn.kind == nkind.N_TPTR && rtn.kind == nkind.N_TPTR) {
+			return mktname(c, "i64");
+		};
+	};
+	if (op == tkind.TK_PLUS    || op == tkind.TK_MINUS  ||
+	    op == tkind.TK_STAR    || op == tkind.TK_SLASH  ||
+	    op == tkind.TK_PERCENT || op == tkind.TK_AMP    ||
+	    op == tkind.TK_PIPE    || op == tkind.TK_CARET  ||
+	    op == tkind.TK_LSHIFT  || op == tkind.TK_RSHIFT) {
+		return unifyarith(c, ltn, rtn);
+	};
+	if (op == tkind.TK_EQ  || op == tkind.TK_NEQ ||
+	    op == tkind.TK_LT  || op == tkind.TK_LE  ||
+	    op == tkind.TK_GT  || op == tkind.TK_GE  ||
+	    op == tkind.TK_AND || op == tkind.TK_OR) {
+		return mktname(c, "bool");
+	};
+	return nil;
+};
+
+// unoptype — derive the result tnode of an N_UN unary expression. Mirrors
+// cstage cmd/wcc/check.c:642-687 `cunop`. The slice/str .len/.cap
+// pseudo-field address-of widening to *i64 mirrors check.c:672-682
+// directly — its purpose is documented at the cstage site.
+fn unoptype(c: *checker, e: *node) *node = {
+	let op: tkind = e.op;
+	let opt: *node = exprtype(c, e.lhs, nil);
+	if (op == tkind.TK_MINUS || op == tkind.TK_PLUS) { return opt; };
+	if (op == tkind.TK_NOT)   { return mktname(c, "bool"); };
+	if (op == tkind.TK_TILDE) { return opt; };
+	if (op == tkind.TK_STAR) {
+		if (opt == nil) { return nil; };
+		let u: *node = resolvealias(c, unwrapbang(opt));
+		if (u == nil) { return nil; };
+		if (u.kind != nkind.N_TPTR) { return nil; };
+		return u.lhs;
+	};
+	if (op == tkind.TK_AMP) {
+		if (e.lhs != nil && e.lhs.kind == nkind.N_DOT) {
+			let fld: str = e.lhs.str;
+			if (streq(fld, "len") || streq(fld, "cap")) {
+				let base: *node = e.lhs.lhs;
+				if (base != nil && base.type_ != nil) {
+					let bu: *tinfo = base.type_: *tinfo;
+					if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
+					if (bu != nil && bu.kind == tykind.TY_PTR)   { bu = bu.sub;   };
+					if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
+					if (bu != nil) {
+						if (bu.kind == tykind.TY_SLICE || bu.kind == tykind.TY_STR) {
+							let pp: *node = newnode(nkind.N_TPTR, "", 0, 0);
+							pp.lhs = mktname(c, "i64");
+							return pp;
+						};
+					};
+				};
+			};
+		};
+		if (opt == nil) { return nil; };
+		let pp: *node = newnode(nkind.N_TPTR, "", 0, 0);
+		pp.lhs = opt;
+		return pp;
+	};
+	return nil;
+};
+
 // exprtype — best-effort type-AST inference for an expression
-// node. Handles literals, identifiers, calls, and casts; returns
-// nil for shapes we don't statically know (binary ops, struct
+// node. Handles literals, identifiers, calls, casts, binary/unary
+// ops; returns nil for shapes we don't statically know (struct
 // field access into non-primitive types, etc).
 // `hint`: optional declared-type AST passed by the caller (let
 // target, assign target). nil = "no hint, derive from self". Threaded
@@ -8240,6 +8351,16 @@ fn exprtype(c: *checker, e: *node, hint: *node) *node = {
 		};
 		return t;
 	};
+	if (k == nkind.N_BIN) {
+		let tn: *node = binoptype(c, e);
+		e.type_ = tinfofornode(c, tn): *void;
+		return tn;
+	};
+	if (k == nkind.N_UN) {
+		let tn: *node = unoptype(c, e);
+		e.type_ = tinfofornode(c, tn): *void;
+		return tn;
+	};
 	if (k == nkind.N_CAST) {
 		// `expr: T` — explicit cast; the type expr is e.rhs. Mirrors
 		// cstage cmd/wcc/check.c:737 `n->type = resolve_type(c, n->rhs)`.
diff --git a/selfhost/cmd/wcc/check.ww b/selfhost/cmd/wcc/check.ww
index 1079e68f..d89e8be2 100644
--- a/selfhost/cmd/wcc/check.ww
+++ b/selfhost/cmd/wcc/check.ww
@@ -1228,9 +1228,120 @@ fn tinfofornode(c: *checker, n: *node) *tinfo = {
 	return r;
 };
 
+// unifyarith — usual-arithmetic-conversion analogue at the AST-tnode
+// layer. Mirrors cstage cmd/wcc/check.c:580-596 `unify_arith`. The
+// trailing typeeq fallback covers same-typed operands; mismatched typed
+// pairs silently return ltn (cstage flags the same shape — wwstage's
+// checker stays silent here per existing discipline).
+fn unifyarith(c: *checker, ltn: *node, rtn: *node) *node = {
+	let lu: bool = isuntypedint(ltn) || isuntypedfloat(ltn);
+	let ru: bool = isuntypedint(rtn) || isuntypedfloat(rtn);
+	if (lu && ru) {
+		if (isuntypedfloat(ltn) || isuntypedfloat(rtn)) {
+			return mktname(c, "untyped_float");
+		};
+		return mktname(c, "untyped_int");
+	};
+	let conf: bool = false;
+	if (lu) {
+		if (isassignable(c, rtn, ltn, &conf)) { return rtn; };
+	};
+	if (ru) {
+		if (isassignable(c, ltn, rtn, &conf)) { return ltn; };
+	};
+	if (typeeqast(ltn, rtn)) { return ltn; };
+	return ltn;
+};
+
+// binoptype — derive the result tnode of an N_BIN operator expression.
+// Mirrors cstage cmd/wcc/check.c:598-640 `cbinop`. Operates on tnodes
+// returned by exprtype; ptr arithmetic / bitwise / shifts / comparisons /
+// logicals all reflect cstage's rules. Type-mismatch diagnostics are
+// elided here (cstage gates the same shape).
+fn binoptype(c: *checker, e: *node) *node = {
+	let op: tkind = e.op;
+	let ltn: *node = exprtype(c, e.lhs, nil);
+	let rtn: *node = exprtype(c, e.rhs, nil);
+	if (op == tkind.TK_PLUS || op == tkind.TK_MINUS) {
+		if (ltn != nil && ltn.kind == nkind.N_TPTR && isinttypeast(rtn)) {
+			return ltn;
+		};
+	};
+	if (op == tkind.TK_PLUS) {
+		if (isinttypeast(ltn) && rtn != nil && rtn.kind == nkind.N_TPTR) {
+			return rtn;
+		};
+	};
+	if (op == tkind.TK_MINUS) {
+		if (ltn != nil && rtn != nil
+		    && ltn.kind == nkind.N_TPTR && rtn.kind == nkind.N_TPTR) {
+			return mktname(c, "i64");
+		};
+	};
+	if (op == tkind.TK_PLUS    || op == tkind.TK_MINUS  ||
+	    op == tkind.TK_STAR    || op == tkind.TK_SLASH  ||
+	    op == tkind.TK_PERCENT || op == tkind.TK_AMP    ||
+	    op == tkind.TK_PIPE    || op == tkind.TK_CARET  ||
+	    op == tkind.TK_LSHIFT  || op == tkind.TK_RSHIFT) {
+		return unifyarith(c, ltn, rtn);
+	};
+	if (op == tkind.TK_EQ  || op == tkind.TK_NEQ ||
+	    op == tkind.TK_LT  || op == tkind.TK_LE  ||
+	    op == tkind.TK_GT  || op == tkind.TK_GE  ||
+	    op == tkind.TK_AND || op == tkind.TK_OR) {
+		return mktname(c, "bool");
+	};
+	return nil;
+};
+
+// unoptype — derive the result tnode of an N_UN unary expression. Mirrors
+// cstage cmd/wcc/check.c:642-687 `cunop`. The slice/str .len/.cap
+// pseudo-field address-of widening to *i64 mirrors check.c:672-682
+// directly — its purpose is documented at the cstage site.
+fn unoptype(c: *checker, e: *node) *node = {
+	let op: tkind = e.op;
+	let opt: *node = exprtype(c, e.lhs, nil);
+	if (op == tkind.TK_MINUS || op == tkind.TK_PLUS) { return opt; };
+	if (op == tkind.TK_NOT)   { return mktname(c, "bool"); };
+	if (op == tkind.TK_TILDE) { return opt; };
+	if (op == tkind.TK_STAR) {
+		if (opt == nil) { return nil; };
+		let u: *node = resolvealias(c, unwrapbang(opt));
+		if (u == nil) { return nil; };
+		if (u.kind != nkind.N_TPTR) { return nil; };
+		return u.lhs;
+	};
+	if (op == tkind.TK_AMP) {
+		if (e.lhs != nil && e.lhs.kind == nkind.N_DOT) {
+			let fld: str = e.lhs.str;
+			if (streq(fld, "len") || streq(fld, "cap")) {
+				let base: *node = e.lhs.lhs;
+				if (base != nil && base.type_ != nil) {
+					let bu: *tinfo = base.type_: *tinfo;
+					if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
+					if (bu != nil && bu.kind == tykind.TY_PTR)   { bu = bu.sub;   };
+					if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
+					if (bu != nil) {
+						if (bu.kind == tykind.TY_SLICE || bu.kind == tykind.TY_STR) {
+							let pp: *node = newnode(nkind.N_TPTR, "", 0, 0);
+							pp.lhs = mktname(c, "i64");
+							return pp;
+						};
+					};
+				};
+			};
+		};
+		if (opt == nil) { return nil; };
+		let pp: *node = newnode(nkind.N_TPTR, "", 0, 0);
+		pp.lhs = opt;
+		return pp;
+	};
+	return nil;
+};
+
 // exprtype — best-effort type-AST inference for an expression
-// node. Handles literals, identifiers, calls, and casts; returns
-// nil for shapes we don't statically know (binary ops, struct
+// node. Handles literals, identifiers, calls, casts, binary/unary
+// ops; returns nil for shapes we don't statically know (struct
 // field access into non-primitive types, etc).
 // `hint`: optional declared-type AST passed by the caller (let
 // target, assign target). nil = "no hint, derive from self". Threaded
@@ -1308,6 +1419,16 @@ fn exprtype(c: *checker, e: *node, hint: *node) *node = {
 		};
 		return t;
 	};
+	if (k == nkind.N_BIN) {
+		let tn: *node = binoptype(c, e);
+		e.type_ = tinfofornode(c, tn): *void;
+		return tn;
+	};
+	if (k == nkind.N_UN) {
+		let tn: *node = unoptype(c, e);
+		e.type_ = tinfofornode(c, tn): *void;
+		return tn;
+	};
 	if (k == nkind.N_CAST) {
 		// `expr: T` — explicit cast; the type expr is e.rhs. Mirrors
 		// cstage cmd/wcc/check.c:737 `n->type = resolve_type(c, n->rhs)`.
diff --git a/selfhost/cmd/wwdump/main.combined.ww b/selfhost/cmd/wwdump/main.combined.ww
index fc2036dd..ed0b2568 100644
--- a/selfhost/cmd/wwdump/main.combined.ww
+++ b/selfhost/cmd/wwdump/main.combined.ww
@@ -8160,9 +8160,120 @@ fn tinfofornode(c: *checker, n: *node) *tinfo = {
 	return r;
 };
 
+// unifyarith — usual-arithmetic-conversion analogue at the AST-tnode
+// layer. Mirrors cstage cmd/wcc/check.c:580-596 `unify_arith`. The
+// trailing typeeq fallback covers same-typed operands; mismatched typed
+// pairs silently return ltn (cstage flags the same shape — wwstage's
+// checker stays silent here per existing discipline).
+fn unifyarith(c: *checker, ltn: *node, rtn: *node) *node = {
+	let lu: bool = isuntypedint(ltn) || isuntypedfloat(ltn);
+	let ru: bool = isuntypedint(rtn) || isuntypedfloat(rtn);
+	if (lu && ru) {
+		if (isuntypedfloat(ltn) || isuntypedfloat(rtn)) {
+			return mktname(c, "untyped_float");
+		};
+		return mktname(c, "untyped_int");
+	};
+	let conf: bool = false;
+	if (lu) {
+		if (isassignable(c, rtn, ltn, &conf)) { return rtn; };
+	};
+	if (ru) {
+		if (isassignable(c, ltn, rtn, &conf)) { return ltn; };
+	};
+	if (typeeqast(ltn, rtn)) { return ltn; };
+	return ltn;
+};
+
+// binoptype — derive the result tnode of an N_BIN operator expression.
+// Mirrors cstage cmd/wcc/check.c:598-640 `cbinop`. Operates on tnodes
+// returned by exprtype; ptr arithmetic / bitwise / shifts / comparisons /
+// logicals all reflect cstage's rules. Type-mismatch diagnostics are
+// elided here (cstage gates the same shape).
+fn binoptype(c: *checker, e: *node) *node = {
+	let op: tkind = e.op;
+	let ltn: *node = exprtype(c, e.lhs, nil);
+	let rtn: *node = exprtype(c, e.rhs, nil);
+	if (op == tkind.TK_PLUS || op == tkind.TK_MINUS) {
+		if (ltn != nil && ltn.kind == nkind.N_TPTR && isinttypeast(rtn)) {
+			return ltn;
+		};
+	};
+	if (op == tkind.TK_PLUS) {
+		if (isinttypeast(ltn) && rtn != nil && rtn.kind == nkind.N_TPTR) {
+			return rtn;
+		};
+	};
+	if (op == tkind.TK_MINUS) {
+		if (ltn != nil && rtn != nil
+		    && ltn.kind == nkind.N_TPTR && rtn.kind == nkind.N_TPTR) {
+			return mktname(c, "i64");
+		};
+	};
+	if (op == tkind.TK_PLUS    || op == tkind.TK_MINUS  ||
+	    op == tkind.TK_STAR    || op == tkind.TK_SLASH  ||
+	    op == tkind.TK_PERCENT || op == tkind.TK_AMP    ||
+	    op == tkind.TK_PIPE    || op == tkind.TK_CARET  ||
+	    op == tkind.TK_LSHIFT  || op == tkind.TK_RSHIFT) {
+		return unifyarith(c, ltn, rtn);
+	};
+	if (op == tkind.TK_EQ  || op == tkind.TK_NEQ ||
+	    op == tkind.TK_LT  || op == tkind.TK_LE  ||
+	    op == tkind.TK_GT  || op == tkind.TK_GE  ||
+	    op == tkind.TK_AND || op == tkind.TK_OR) {
+		return mktname(c, "bool");
+	};
+	return nil;
+};
+
+// unoptype — derive the result tnode of an N_UN unary expression. Mirrors
+// cstage cmd/wcc/check.c:642-687 `cunop`. The slice/str .len/.cap
+// pseudo-field address-of widening to *i64 mirrors check.c:672-682
+// directly — its purpose is documented at the cstage site.
+fn unoptype(c: *checker, e: *node) *node = {
+	let op: tkind = e.op;
+	let opt: *node = exprtype(c, e.lhs, nil);
+	if (op == tkind.TK_MINUS || op == tkind.TK_PLUS) { return opt; };
+	if (op == tkind.TK_NOT)   { return mktname(c, "bool"); };
+	if (op == tkind.TK_TILDE) { return opt; };
+	if (op == tkind.TK_STAR) {
+		if (opt == nil) { return nil; };
+		let u: *node = resolvealias(c, unwrapbang(opt));
+		if (u == nil) { return nil; };
+		if (u.kind != nkind.N_TPTR) { return nil; };
+		return u.lhs;
+	};
+	if (op == tkind.TK_AMP) {
+		if (e.lhs != nil && e.lhs.kind == nkind.N_DOT) {
+			let fld: str = e.lhs.str;
+			if (streq(fld, "len") || streq(fld, "cap")) {
+				let base: *node = e.lhs.lhs;
+				if (base != nil && base.type_ != nil) {
+					let bu: *tinfo = base.type_: *tinfo;
+					if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
+					if (bu != nil && bu.kind == tykind.TY_PTR)   { bu = bu.sub;   };
+					if (bu != nil && bu.kind == tykind.TY_NAMED) { bu = bu.under; };
+					if (bu != nil) {
+						if (bu.kind == tykind.TY_SLICE || bu.kind == tykind.TY_STR) {
+							let pp: *node = newnode(nkind.N_TPTR, "", 0, 0);
+							pp.lhs = mktname(c, "i64");
+							return pp;
+						};
+					};
+				};
+			};
+		};
+		if (opt == nil) { return nil; };
+		let pp: *node = newnode(nkind.N_TPTR, "", 0, 0);
+		pp.lhs = opt;
+		return pp;
+	};
+	return nil;
+};
+
 // exprtype — best-effort type-AST inference for an expression
-// node. Handles literals, identifiers, calls, and casts; returns
-// nil for shapes we don't statically know (binary ops, struct
+// node. Handles literals, identifiers, calls, casts, binary/unary
+// ops; returns nil for shapes we don't statically know (struct
 // field access into non-primitive types, etc).
 // `hint`: optional declared-type AST passed by the caller (let
 // target, assign target). nil = "no hint, derive from self". Threaded
@@ -8240,6 +8351,16 @@ fn exprtype(c: *checker, e: *node, hint: *node) *node = {
 		};
 		return t;
 	};
+	if (k == nkind.N_BIN) {
+		let tn: *node = binoptype(c, e);
+		e.type_ = tinfofornode(c, tn): *void;
+		return tn;
+	};
+	if (k == nkind.N_UN) {
+		let tn: *node = unoptype(c, e);
+		e.type_ = tinfofornode(c, tn): *void;
+		return tn;
+	};
 	if (k == nkind.N_CAST) {
 		// `expr: T` — explicit cast; the type expr is e.rhs. Mirrors
 		// cstage cmd/wcc/check.c:737 `n->type = resolve_type(c, n->rhs)`.