diff --git a/src/runtime/c/pgf/expr.c b/src/runtime/c/pgf/expr.c
index cedb25989..6f2de5a6b 100644
--- a/src/runtime/c/pgf/expr.c
+++ b/src/runtime/c/pgf/expr.c
@@ -390,18 +390,38 @@ pgf_print_hypo(PgfHypo *hypo, int prec, GuWriter *wtr, GuExn *err)
 void
 pgf_print_type(PgfType *type, int prec, GuWriter *wtr, GuExn *err)
 {
-    size_t len = gu_seq_length(type->hypos);
-    for (size_t i = 0; i < len; i++) {
-        PgfHypo *hypo = gu_seq_index(type->hypos, PgfHypo, i);
-        pgf_print_hypo(hypo, 1, wtr, err);
-
-        gu_puts(" -> ", wtr, err);
-    }
-
-    gu_string_write(type->cid, wtr, err);
+    size_t n_hypos = gu_seq_length(type->hypos);
     
-    for (int i = 0; i < type->n_exprs; i++) {
-        gu_puts(" ", wtr, err);
-        pgf_print_expr(type->exprs[i], 4, wtr, err);
-    }
+    if (n_hypos > 0) {
+		if (prec > 0) gu_putc('(', wtr, err);
+		
+		for (size_t i = 0; i < n_hypos; i++) {
+			PgfHypo *hypo = gu_seq_index(type->hypos, PgfHypo, i);
+			pgf_print_hypo(hypo, 1, wtr, err);
+
+			gu_puts(" -> ", wtr, err);
+		}
+
+		gu_string_write(type->cid, wtr, err);
+    
+		for (int i = 0; i < type->n_exprs; i++) {
+			gu_puts(" ", wtr, err);
+			pgf_print_expr(type->exprs[i], 4, wtr, err);
+		}
+		
+		if (prec > 0) gu_putc(')', wtr, err);
+	} else if (type->n_exprs > 0) {
+		if (prec > 3) gu_putc('(', wtr, err);
+		
+		gu_string_write(type->cid, wtr, err);
+    
+		for (int i = 0; i < type->n_exprs; i++) {
+			gu_puts(" ", wtr, err);
+			pgf_print_expr(type->exprs[i], 4, wtr, err);
+		}
+		
+		if (prec > 3) gu_putc(')', wtr, err);
+	} else {
+		gu_string_write(type->cid, wtr, err);
+	}
 }
diff --git a/src/runtime/c/pgf/printer.c b/src/runtime/c/pgf/printer.c
new file mode 100644
index 000000000..52135912b
--- /dev/null
+++ b/src/runtime/c/pgf/printer.c
@@ -0,0 +1,357 @@
+#include <pgf/data.h>
+
+typedef struct {
+	GuMapItor fn;
+	GuWriter* wtr;
+} PgfPrintFn;
+
+void
+pgf_print_flag(GuMapItor* fn, const void* key, void* value,
+			GuExn* err)
+{
+	PgfPrintFn* clo = (PgfPrintFn*) fn;
+    PgfCId flag = *((PgfCId *) key);
+    PgfLiteral lit = *((PgfLiteral *) value);
+    GuWriter *wtr = clo->wtr;
+    
+    gu_puts("  flag ", wtr, err);
+    gu_string_write(flag, wtr, err);
+    gu_puts(" = ", wtr, err);
+    pgf_print_literal(lit, wtr, err);
+    gu_puts(";\n", wtr, err);
+}
+
+void
+pgf_print_cat(GuMapItor* fn, const void* key, void* value,
+			GuExn* err)
+{
+	PgfPrintFn* clo = (PgfPrintFn*) fn;
+    PgfCId name = *((PgfCId *) key);
+    PgfCat *cat  = *((PgfCat **) value);
+    GuWriter *wtr = clo->wtr;
+
+    gu_puts("  cat ", wtr, err);
+    gu_string_write(name, wtr, err);
+
+    size_t n_hypos = gu_seq_length(cat->context);
+    for (size_t i = 0; i < n_hypos; i++) {
+		PgfHypo* hypo = gu_seq_get(cat->context, PgfHypo*, i);
+		gu_putc(' ', wtr, err);
+		pgf_print_hypo(hypo, 4, wtr, err);
+	}
+
+    gu_puts(" ;\n", wtr, err);
+}
+
+void
+pgf_print_absfun(GuMapItor* fn, const void* key, void* value,
+			GuExn* err)
+{
+	PgfPrintFn* clo = (PgfPrintFn*) fn;
+    PgfCId name = *((PgfCId *) key);
+    PgfFunDecl *fun = *((PgfFunDecl **) value);
+    GuWriter *wtr = clo->wtr;
+    
+    gu_puts(gu_seq_is_null(fun->defns) ? "  data " : "  fun ", wtr, err);
+    gu_string_write(name, wtr, err);
+    gu_puts(" : ", wtr, err);
+    pgf_print_type(fun->type, 0, wtr, err);
+    gu_puts(" ;\n", wtr, err);
+}
+static void
+pgf_print_abstract(PgfCId absname, PgfAbstr* abstr, 
+                   GuWriter* wtr, GuExn* err)
+{
+	gu_puts("abstract ", wtr, err);
+	gu_string_write(absname, wtr, err);
+	gu_puts(" {\n", wtr, err);
+	
+	PgfPrintFn clo1 = { { pgf_print_flag }, wtr };
+	gu_map_iter(abstr->aflags, &clo1.fn, err);
+
+	PgfPrintFn clo2 = { { pgf_print_cat }, wtr };
+	gu_map_iter(abstr->cats, &clo2.fn, err);
+
+	PgfPrintFn clo3 = { { pgf_print_absfun }, wtr };
+	gu_map_iter(abstr->funs, &clo3.fn, err);
+	
+	gu_puts("}\n", wtr, err);
+}
+
+static void
+pgf_print_productions(GuMapItor* fn, const void* key, void* value,
+			GuExn* err)
+{
+	PgfPrintFn* clo = (PgfPrintFn*) fn;
+    int fid = *((int *) key);
+    PgfCCat* ccat = *((PgfCCat**) value);
+    GuWriter *wtr = clo->wtr;
+
+	if (!gu_seq_is_null(ccat->prods)) {
+		size_t n_prods = gu_seq_length(ccat->prods);
+		for (size_t i = 0; i < n_prods; i++) {
+			PgfProduction prod = gu_seq_get(ccat->prods, PgfProduction, i);
+		
+			gu_printf(wtr,err,"    C%d -> ",fid);
+
+			GuVariantInfo i = gu_variant_open(prod);
+			switch (i.tag) {
+			case PGF_PRODUCTION_APPLY: {
+				PgfProductionApply* papp = i.data;
+				gu_printf(wtr,err,"F%d[",papp->fun->funid);
+				size_t n_args = gu_seq_length(papp->args);
+				for (size_t j = 0; j < n_args; j++) {
+					if (j > 0)
+						gu_putc(',',wtr,err);
+                    
+					PgfPArg arg = gu_seq_get(papp->args, PgfPArg, j);
+
+					if (arg.hypos != NULL) {
+						size_t n_hypos = gu_list_length(arg.hypos);
+						for (size_t k = 0; k < n_hypos; k++) {
+							if (k > 0)
+								gu_putc(' ',wtr,err);
+							PgfCCat *hypo = gu_list_index(arg.hypos, k);
+							gu_printf(wtr,err,"C%d",hypo->fid);
+						}
+					}
+            
+					gu_printf(wtr,err,"C%d",arg.ccat->fid);
+				}
+				gu_printf(wtr,err,"]\n");
+				break;
+			}
+			case PGF_PRODUCTION_COERCE: {
+				PgfProductionCoerce* pcoerce = i.data;
+				gu_printf(wtr,err,"_[C%d]\n",pcoerce->coerce);
+				break;
+			}
+			default:
+				gu_impossible();
+			}
+		}
+	}
+}
+
+static void
+pgf_print_lindefs(GuMapItor* fn, const void* key, void* value,
+			GuExn* err)
+{
+	PgfPrintFn* clo = (PgfPrintFn*) fn;
+    int fid = *((int *) key);
+    PgfCCat* ccat = *((PgfCCat**) value);
+    GuWriter *wtr = clo->wtr;
+    
+    if (ccat->lindefs != NULL) {
+		gu_printf(wtr,err,"    C%d -> ",fid);
+		
+		size_t n_lindefs = gu_list_length(ccat->lindefs);
+		for (size_t i = 0; i < n_lindefs; i++) {
+			if (i > 0) gu_putc(' ', wtr, err);
+			
+			PgfFunId funid = gu_list_index(ccat->lindefs, i);
+			gu_printf(wtr,err,"F%d",funid->funid);
+		}
+		
+		gu_putc('\n', wtr,err);
+	}
+}
+
+static void
+pgf_print_cncfun(PgfCncFun *cncfun, PgfSequences *sequences, 
+					GuWriter *wtr, GuExn *err)
+{
+	gu_printf(wtr,err,"    F%d := (", cncfun->funid);
+	
+	size_t n_seqs = gu_list_length(sequences);
+	
+	for (size_t i = 0; i < cncfun->n_lins; i++) {
+		if (i > 0) gu_putc(',', wtr, err);
+		PgfSequence seq = cncfun->lins[i];
+
+		for (size_t seqid = 0; seqid < n_seqs; seqid++) {
+			if (gu_seq_data(gu_list_index(sequences, seqid)) == gu_seq_data(seq)) {
+				gu_printf(wtr,err,"S%d", seqid);
+				break;
+			}
+		}
+	}
+	
+	gu_puts(") [", wtr, err);
+	gu_string_write(cncfun->fun, wtr, err);
+	gu_puts("]\n", wtr, err);
+}
+
+static void
+pgf_print_tokens(PgfTokens tokens, GuWriter *wtr, GuExn *err)
+{
+	gu_putc('"', wtr, err);
+	size_t n_toks = gu_seq_length(tokens);
+	for (size_t i = 0; i < n_toks; i++) {
+		if (i > 0) gu_putc(' ', wtr, err);
+			
+		PgfToken tok = gu_seq_get(tokens, PgfToken, i);
+		gu_string_write(tok, wtr, err);
+	}
+	gu_putc('"', wtr, err);
+}
+
+void
+pgf_print_symbol(PgfSymbol sym, GuWriter *wtr, GuExn *err)
+{
+	switch (gu_variant_tag(sym)) {
+	case PGF_SYMBOL_CAT: {
+		PgfSymbolCat* scat = gu_variant_data(sym);
+		gu_printf(wtr, err, "<%d,%d>", scat->d, scat->r);
+		break;
+	}
+	case PGF_SYMBOL_KS: {
+		PgfSymbolKS* sks = gu_variant_data(sym);
+		pgf_print_tokens(sks->tokens, wtr, err);
+		break;
+	}
+	case PGF_SYMBOL_KP: {
+		PgfSymbolKP* skp = gu_variant_data(sym);
+
+		gu_puts("pre {", wtr, err);
+		pgf_print_tokens(skp->default_form, wtr, err);
+		
+		for (size_t i = 0; i < skp->n_forms; i++) {
+			gu_puts("; ", wtr, err);
+            pgf_print_tokens(skp->forms[i].form, wtr, err);
+            gu_puts(" / ", wtr, err);
+            
+            size_t n_prefixes = gu_list_length(skp->forms[i].prefixes);
+            for (size_t j = 0; j < n_prefixes; j++) {
+				if (j > 0) gu_putc(' ', wtr, err);
+				
+				GuString prefix = gu_list_index(skp->forms[i].prefixes, j);
+				gu_putc('"', wtr, err);
+				gu_string_write(prefix, wtr, err);
+				gu_putc('"', wtr, err);
+			}
+		}
+		
+		gu_puts("}", wtr, err);
+		break;
+	}
+	case PGF_SYMBOL_LIT: {
+		PgfSymbolLit *slit = gu_variant_data(sym);
+		gu_printf(wtr, err, "{%d,%d}", slit->d, slit->r);
+		break;
+	}
+	case PGF_SYMBOL_VAR: {
+		PgfSymbolVar *svar = gu_variant_data(sym);
+		gu_printf(wtr, err, "<%d,$%d>", svar->d, svar->r);
+		break;
+	}
+	default:
+		gu_impossible();
+	}
+}
+
+static void
+pgf_print_sequence(size_t seqid, PgfSequence seq, GuWriter *wtr, GuExn *err)
+{
+	gu_printf(wtr,err,"    S%d := ", seqid);
+
+	int n_syms = gu_seq_length(seq);
+	for (int i = 0; i < n_syms; i++) {
+		if (i > 0) gu_putc(' ', wtr, err);
+			
+		PgfSymbol sym = gu_seq_get(seq, PgfSymbol, i);
+		pgf_print_symbol(sym, wtr, err);
+	}
+
+	gu_putc('\n', wtr, err);
+}
+
+static void
+pgf_print_cnccat(GuMapItor* fn, const void* key, void* value,
+			GuExn* err)
+{
+	PgfPrintFn* clo = (PgfPrintFn*) fn;
+    PgfCId name = *((PgfCId *) key);
+    PgfCncCat* cnccat = *((PgfCncCat**) value);
+    GuWriter *wtr = clo->wtr;
+    
+    gu_puts("    ", wtr, err);
+    gu_string_write(name, wtr, err);
+    gu_puts(" :=\n", wtr, err);
+    
+    PgfCCat *start = gu_list_index(cnccat->cats, 0);
+    PgfCCat *end   = gu_list_index(cnccat->cats, gu_list_length(cnccat->cats)-1);
+    
+    gu_printf(wtr, err, "       range  [C%d..C%d]\n", start->fid, end->fid);
+    
+    gu_puts("       labels [", wtr, err);
+    for (size_t i = 0; i < cnccat->n_lins; i++) {
+		if (i > 0) {
+			gu_puts("\n               ", wtr, err);
+		}
+
+		GuString lbl = gu_list_index(cnccat->labels, i);
+		gu_string_write(lbl, wtr, err);
+	}
+    gu_puts("]\n", wtr, err);
+}
+
+static void
+pgf_print_concrete(PgfCId cncname, PgfConcr* concr, 
+                   GuWriter* wtr, GuExn* err)
+{
+	gu_puts("concrete ", wtr, err);
+	gu_string_write(cncname, wtr, err);
+	gu_puts(" {\n", wtr, err);
+
+	PgfPrintFn clo1 = { { pgf_print_flag }, wtr };
+	gu_map_iter(concr->cflags, &clo1.fn, err);
+
+	gu_puts("  productions\n", wtr, err);
+	PgfPrintFn clo2 = { { pgf_print_productions }, wtr };
+	gu_map_iter(concr->ccats, &clo2.fn, err);
+
+	gu_puts("  lindefs\n", wtr, err);
+	PgfPrintFn clo3 = { { pgf_print_lindefs }, wtr };
+	gu_map_iter(concr->ccats, &clo3.fn, err);
+
+	gu_puts("  lin\n", wtr, err);
+	size_t n_funs = gu_list_length(concr->cncfuns);
+	for (size_t i = 0; i < n_funs; i++) {
+		PgfCncFun* cncfun = gu_list_index(concr->cncfuns, i);
+		pgf_print_cncfun(cncfun, concr->sequences, wtr, err);
+	}
+
+	gu_puts("  sequences\n", wtr, err);
+	size_t n_seqs = gu_list_length(concr->sequences);
+	for (size_t i = 0; i < n_seqs; i++) {
+		PgfSequence seq = gu_list_index(concr->sequences, i);
+		pgf_print_sequence(i, seq, wtr, err);
+	}
+	
+	gu_puts("  categories\n", wtr, err);
+	PgfPrintFn clo4 = { { pgf_print_cnccat }, wtr };
+	gu_map_iter(concr->cnccats, &clo4.fn, err);
+	
+	gu_puts("}\n", wtr, err);
+}
+
+static void
+pgf_print_concr_cb(GuMapItor* fn, const void* key, void* value,
+			GuExn* err)
+{
+	PgfPrintFn* clo = (PgfPrintFn*) fn;
+    PgfCId cncname = *((PgfCId *) key);
+    PgfConcr *concr = *((PgfConcr **) value);
+
+	pgf_print_concrete(cncname, concr, clo->wtr, err);
+}
+
+void
+pgf_print(PgfPGF* pgf, GuWriter* wtr, GuExn* err)
+{
+	pgf_print_abstract(pgf->absname, &pgf->abstract, wtr, err);
+	
+	PgfPrintFn clo = { { pgf_print_concr_cb }, wtr };
+	gu_map_iter(pgf->concretes, &clo.fn, err);
+}