diff --git a/src/ast/ast.h b/src/ast/ast.h
index 779913f17..388776343 100644
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@@ -2201,10 +2201,12 @@ public:
     app * mk_xor(expr * lhs, expr * rhs) { return mk_app(basic_family_id, OP_XOR, lhs, rhs); }
     app * mk_ite(expr * c, expr * t, expr * e) { return mk_app(basic_family_id, OP_ITE, c, t, e); }
     app * mk_xor(unsigned num_args, expr * const * args) { return mk_app(basic_family_id, OP_XOR, num_args, args); }
-    app * mk_xor(ptr_buffer<expr> const& args) { return mk_xor(args.size(), args.data()); }
-    app * mk_xor(ptr_vector<expr> const& args) { return mk_xor(args.size(), args.data()); }
-    app * mk_xor(ref_buffer<expr, ast_manager> const& args) { return mk_xor(args.size(), args.data()); }
+    app * mk_xor(std::span<expr* const> args) { return mk_app(basic_family_id, OP_XOR, args); }
+    app * mk_xor(ptr_buffer<expr> const& args) { return mk_xor(std::span<expr* const>(args.data(), args.size())); }
+    app * mk_xor(ptr_vector<expr> const& args) { return mk_xor(std::span<expr* const>(args.data(), args.size())); }
+    app * mk_xor(ref_buffer<expr, ast_manager> const& args) { return mk_xor(std::span<expr* const>(args.data(), args.size())); }
     app * mk_or(unsigned num_args, expr * const * args) { return mk_app(basic_family_id, OP_OR, num_args, args); }
+    app * mk_or(std::span<expr* const> args) { return mk_app(basic_family_id, OP_OR, args); }
     app * mk_and(std::span<expr* const> args) { return mk_app(basic_family_id, OP_AND, args); }
     app * mk_or(expr * arg1, expr * arg2) { return mk_app(basic_family_id, OP_OR, arg1, arg2); }
     app * mk_and(expr * arg1, expr * arg2) { return mk_app(basic_family_id, OP_AND, arg1, arg2); }
@@ -2216,10 +2218,10 @@ public:
     app * mk_and(ptr_vector<expr> const& args) { return mk_and(std::span<expr* const>(args.data(), args.size())); }
     app * mk_and(ref_buffer<expr, ast_manager> const& args) { return mk_and(std::span<expr* const>(args.data(), args.size())); }
     app * mk_and(ptr_buffer<expr> const& args) { return mk_and(std::span<expr* const>(args.data(), args.size())); }
-    app * mk_or(ref_vector<expr, ast_manager> const& args) { return mk_or(args.size(), args.data()); }
-    app * mk_or(ptr_vector<expr> const& args) { return mk_or(args.size(), args.data()); }
-    app * mk_or(ref_buffer<expr, ast_manager> const& args) { return mk_or(args.size(), args.data()); }
-    app * mk_or(ptr_buffer<expr> const& args) { return mk_or(args.size(), args.data()); }
+    app * mk_or(ref_vector<expr, ast_manager> const& args) { return mk_or(std::span<expr* const>(args.data(), args.size())); }
+    app * mk_or(ptr_vector<expr> const& args) { return mk_or(std::span<expr* const>(args.data(), args.size())); }
+    app * mk_or(ref_buffer<expr, ast_manager> const& args) { return mk_or(std::span<expr* const>(args.data(), args.size())); }
+    app * mk_or(ptr_buffer<expr> const& args) { return mk_or(std::span<expr* const>(args.data(), args.size())); }
     app * mk_implies(expr * arg1, expr * arg2) { return mk_app(basic_family_id, OP_IMPLIES, arg1, arg2); }
     app * mk_not(expr * n) { return mk_app(basic_family_id, OP_NOT, n); }
     app * mk_distinct(unsigned num_args, expr * const * args);
diff --git a/src/ast/normal_forms/nnf.cpp b/src/ast/normal_forms/nnf.cpp
index efd5784cf..ee611d1ac 100644
--- a/src/ast/normal_forms/nnf.cpp
+++ b/src/ast/normal_forms/nnf.cpp
@@ -472,7 +472,7 @@ struct nnf::imp {
         if (m.is_and(t) == fr.m_pol)
             r = m.mk_and(std::span<expr* const>(m_result_stack.data() + fr.m_spos, t->get_num_args()));
         else
-            r = m.mk_or(t->get_num_args(), m_result_stack.data() + fr.m_spos);
+            r = m.mk_or(std::span<expr* const>(m_result_stack.data() + fr.m_spos, t->get_num_args()));
         
         m_result_stack.shrink(fr.m_spos);
         m_result_stack.push_back(r);
@@ -522,7 +522,7 @@ struct nnf::imp {
 
         app * r;
         if (fr.m_pol)
-            r = m.mk_or(2, m_result_stack.data() + fr.m_spos);
+            r = m.mk_or(std::span<expr* const>(m_result_stack.data() + fr.m_spos, 2));
         else
             r = m.mk_and(std::span<expr* const>(m_result_stack.data() + fr.m_spos, 2));
         
diff --git a/src/muz/spacer/spacer_context.cpp b/src/muz/spacer/spacer_context.cpp
index 8ee2a3f7f..c6553b2ba 100644
--- a/src/muz/spacer/spacer_context.cpp
+++ b/src/muz/spacer/spacer_context.cpp
@@ -1970,7 +1970,7 @@ void pred_transformer::update_solver_with_rfs(prop_solver *solver,
         }
         else {
             expr *args[4] = { not_rule_tag, last_tag, rf->get(), rf->tag() };
-            e = m.mk_or(4, args);
+            e = m.mk_or(args);
         }
         last_tag = m.mk_not(rf->tag());
         pm.formula_n2o(e.get(), e, pos);
diff --git a/src/qe/nlarith_util.cpp b/src/qe/nlarith_util.cpp
index 60ff87537..a66db0803 100644
--- a/src/qe/nlarith_util.cpp
+++ b/src/qe/nlarith_util.cpp
@@ -344,7 +344,7 @@ namespace nlarith {
 
         app* mk_or(expr* a, expr* b) {
             expr* args[2] = { a, b };
-            return mk_or(2, args);
+            return mk_or(args);
         }
         void display_branching(
             std::ostream& out, app* x,
diff --git a/src/smt/dyn_ack.cpp b/src/smt/dyn_ack.cpp
index 1c66427e2..14bfcae2b 100644
--- a/src/smt/dyn_ack.cpp
+++ b/src/smt/dyn_ack.cpp
@@ -156,7 +156,7 @@ namespace smt {
             p5 = m.mk_unit_resolution(2, ps);
             SASSERT(m.get_fact(p5) == m.mk_false());
             expr* eqs[3] = { m.mk_not(m_eq1), m.mk_not(m_eq2), m_eq3 };
-            expr_ref conclusion(m.mk_or(3, eqs), m);
+            expr_ref conclusion(m.mk_or(eqs), m);
             p6 = m.mk_lemma(p5, conclusion);
             return p6;
         }