diff --git a/src/ast/array_decl_plugin.cpp b/src/ast/array_decl_plugin.cpp
index 198514671..2120a5578 100644
--- a/src/ast/array_decl_plugin.cpp
+++ b/src/ast/array_decl_plugin.cpp
@@ -17,6 +17,7 @@ Revision History:
 
 --*/
 #include<sstream>
+#include<format>
 #include "ast/array_decl_plugin.h"
 #include "util/warning.h"
 #include "ast/ast_pp.h"
@@ -139,10 +140,8 @@ func_decl * array_decl_plugin::mk_const(sort * s, unsigned arity, sort * const *
 
 func_decl * array_decl_plugin::mk_map(func_decl* f, unsigned arity, sort* const* domain) {
     if (arity != f->get_arity()) {
-        std::ostringstream buffer;
-        buffer << "map expects to take as many arguments as the function being mapped, "
-               << "it was given " << arity << " but expects " << f->get_arity();
-        m_manager->raise_exception(buffer.str());
+        m_manager->raise_exception(std::format("map expects to take as many arguments as the function being mapped, it was given {} but expects {}",
+                                                arity, f->get_arity()));
         return nullptr;
     }
     if (arity == 0) {
@@ -157,32 +156,21 @@ func_decl * array_decl_plugin::mk_map(func_decl* f, unsigned arity, sort* const*
     unsigned dom_arity = get_array_arity(domain[0]);
     for (unsigned i = 0; i < arity; ++i) {
         if (!is_array_sort(domain[i])) {
-            std::ostringstream buffer;
-            buffer << "map expects an array sort as argument at position " << i;
-            m_manager->raise_exception(buffer.str());
+            m_manager->raise_exception(std::format("map expects an array sort as argument at position {}", i));
             return nullptr;
         }
         if (get_array_arity(domain[i]) != dom_arity) {
-            std::ostringstream buffer;
-            buffer << "map expects all arguments to have the same array domain,  "
-                   << "this is not the case for argument " << i;
-            m_manager->raise_exception(buffer.str());
+            m_manager->raise_exception(std::format("map expects all arguments to have the same array domain,  this is not the case for argument {}", i));
             return nullptr;
         }
         for (unsigned j = 0; j < dom_arity; ++j) {
             if (get_array_domain(domain[i],j) != get_array_domain(domain[0],j)) {
-                std::ostringstream buffer;
-                buffer << "map expects all arguments to have the same array domain, "
-                       << "this is not the case for argument " << i;
-                m_manager->raise_exception(buffer.str());
+                m_manager->raise_exception(std::format("map expects all arguments to have the same array domain, this is not the case for argument {}", i));
                 return nullptr;
             }
         }
         if (get_array_range(domain[i]) != f->get_domain(i)) {
-            std::ostringstream buffer;
-            buffer << "map expects the argument at position " << i 
-                   << " to have the array range the same as the function";
-            m_manager->raise_exception(buffer.str());
+            m_manager->raise_exception(std::format("map expects the argument at position {} to have the array range the same as the function", i));
             return nullptr;
         }
     }
@@ -243,9 +231,8 @@ func_decl* array_decl_plugin::mk_select(unsigned arity, sort * const * domain) {
     parameter const* parameters = s->get_parameters();
  
     if (num_parameters != arity) {
-        std::stringstream strm;
-        strm << "select requires " << num_parameters << " arguments, but was provided with " << arity << " arguments";
-        m_manager->raise_exception(strm.str());
+        m_manager->raise_exception(std::format("select requires {} arguments, but was provided with {} arguments", 
+                                                num_parameters, arity));
         return nullptr;
     }
     ptr_buffer<sort> new_domain; // we need this because of coercions.
@@ -254,10 +241,9 @@ func_decl* array_decl_plugin::mk_select(unsigned arity, sort * const * domain) {
         if (!parameters[i].is_ast() || 
             !is_sort(parameters[i].get_ast()) || 
             !m_manager->compatible_sorts(domain[i+1], to_sort(parameters[i].get_ast()))) {
-            std::stringstream strm;
-            strm << "domain sort " << sort_ref(domain[i+1], *m_manager) << " and parameter ";
-            strm << parameter_pp(parameters[i], *m_manager) << " do not match";
-            m_manager->raise_exception(strm.str());
+            m_manager->raise_exception(std::format("domain sort {} and parameter {} do not match",
+                                                    to_string(sort_ref(domain[i+1], *m_manager)),
+                                                    to_string(parameter_pp(parameters[i], *m_manager))));
             return nullptr;
         }
         new_domain.push_back(to_sort(parameters[i].get_ast()));
@@ -281,10 +267,8 @@ func_decl * array_decl_plugin::mk_store(unsigned arity, sort * const * domain) {
         return nullptr;
     }
     if (arity != num_parameters+1) {
-        std::ostringstream buffer;
-        buffer << "store expects the first argument to be an array taking " << num_parameters+1 
-               << ", instead it was passed " << (arity - 1) << "arguments";
-        m_manager->raise_exception(buffer.str());
+        m_manager->raise_exception(std::format("store expects the first argument to be an array taking {}, instead it was passed {}arguments",
+                                                num_parameters+1, arity - 1));
         UNREACHABLE();
         return nullptr;
     }
@@ -298,9 +282,9 @@ func_decl * array_decl_plugin::mk_store(unsigned arity, sort * const * domain) {
         sort* srt1 = to_sort(parameters[i].get_ast());
         sort* srt2 = domain[i+1];
         if (!m_manager->compatible_sorts(srt1, srt2)) {
-            std::stringstream strm;
-            strm << "domain sort " << sort_ref(srt2, *m_manager) << " and parameter sort " << sort_ref(srt1, *m_manager) << " do not match";
-            m_manager->raise_exception(strm.str());
+            m_manager->raise_exception(std::format("domain sort {} and parameter sort {} do not match",
+                                                    to_string(sort_ref(srt2, *m_manager)),
+                                                    to_string(sort_ref(srt1, *m_manager))));
             UNREACHABLE();
             return nullptr;
         }
@@ -333,15 +317,11 @@ func_decl * array_decl_plugin::mk_array_ext(unsigned arity, sort * const * domai
 bool array_decl_plugin::check_set_arguments(unsigned arity, sort * const * domain) {
     for (unsigned i = 0; i < arity; ++i) {
         if (domain[i] != domain[0]) {
-            std::ostringstream buffer;
-            buffer << "arguments " << 1 << " and " << (i+1) << " have different sorts";
-            m_manager->raise_exception(buffer.str());
+            m_manager->raise_exception(std::format("arguments {} and {} have different sorts", 1, i+1));
             return false;
         }
         if (domain[i]->get_family_id() != m_family_id) {
-            std::ostringstream buffer;
-            buffer << "argument " << (i+1) << " is not of array sort";
-            m_manager->raise_exception(buffer.str());
+            m_manager->raise_exception(std::format("argument {} is not of array sort", i+1));
             return false;
         }
     }
diff --git a/src/ast/ast.cpp b/src/ast/ast.cpp
index 6e2f2e6af..11e64c677 100644
--- a/src/ast/ast.cpp
+++ b/src/ast/ast.cpp
@@ -17,6 +17,7 @@ Revision History:
 
 --*/
 #include <sstream>
+#include <format>
 #include <cstring>
 #include "ast/ast.h"
 #include "ast/ast_pp.h"
@@ -1021,9 +1022,9 @@ sort* basic_decl_plugin::join(sort* s1, sort* s2) {
         return s2;
     if (s2 == m_bool_sort && s1->get_family_id() == arith_family_id)
         return s1;
-    std::ostringstream buffer;
-    buffer << "Sorts " << mk_pp(s1, *m_manager) << " and " << mk_pp(s2, *m_manager) << " are incompatible";
-    throw ast_exception(buffer.str());
+    throw ast_exception(std::format("Sorts {} and {} are incompatible", 
+                                     to_string(mk_pp(s1, *m_manager)), 
+                                     to_string(mk_pp(s2, *m_manager))));
 }
 
 
@@ -1700,10 +1701,8 @@ ast * ast_manager::register_node_core(ast * n) {
         SASSERT(contains);
         SASSERT(m_ast_table.contains(n));
         if (is_func_decl(r) && to_func_decl(r)->get_range() != to_func_decl(n)->get_range()) {
-            std::ostringstream buffer;
-            buffer << "Recycling of declaration for the same name '" << to_func_decl(r)->get_name().str()
-                   << "' and domain, but different range type is not permitted";
-            throw ast_exception(buffer.str());
+            throw ast_exception(std::format("Recycling of declaration for the same name '{}' and domain, but different range type is not permitted",
+                                             to_func_decl(r)->get_name().str()));
         }
         deallocate_node(n, ::get_node_size(n));
         return r;
@@ -2022,11 +2021,11 @@ void ast_manager::check_sort(func_decl const * decl, unsigned num_args, expr * c
         for (unsigned i = 0; i < num_args; i++) {
             sort * given = args[i]->get_sort();
             if (!compatible_sorts(expected, given)) {
-                std::ostringstream buff;
-                buff << "invalid function application for " << decl->get_name() << ", ";
-                buff << "sort mismatch on argument at position " << (i+1) << ", ";
-                buff << "expected " << mk_pp(expected, m) << " but given " << mk_pp(given, m);
-                throw ast_exception(buff.str());
+                throw ast_exception(std::format("invalid function application for {}, sort mismatch on argument at position {}, expected {} but given {}",
+                                                 to_string(decl->get_name()),
+                                                 i + 1,
+                                                 to_string(mk_pp(expected, m)),
+                                                 to_string(mk_pp(given, m))));
             }
         }
     }
@@ -2038,11 +2037,11 @@ void ast_manager::check_sort(func_decl const * decl, unsigned num_args, expr * c
             sort * expected = decl->get_domain(i);
             sort * given    = args[i]->get_sort();
             if (!compatible_sorts(expected, given)) {
-                std::ostringstream buff;
-                buff << "invalid function application for " << decl->get_name() << ", ";
-                buff << "sort mismatch on argument at position " << (i+1) << ", ";
-                buff << "expected " << mk_pp(expected, m) << " but given " << mk_pp(given, m);
-                throw ast_exception(buff.str());
+                throw ast_exception(std::format("invalid function application for {}, sort mismatch on argument at position {}, expected {} but given {}",
+                                                 to_string(decl->get_name()),
+                                                 i + 1,
+                                                 to_string(mk_pp(expected, m)),
+                                                 to_string(mk_pp(given, m))));
             }
         }
     }
@@ -2197,12 +2196,10 @@ void ast_manager::check_args(func_decl* f, unsigned n, expr* const* es) {
         sort * actual_sort   = es[i]->get_sort();
         sort * expected_sort = f->is_associative() ? f->get_domain(0) : f->get_domain(i);
         if (expected_sort != actual_sort) {
-            std::ostringstream buffer;
-            buffer << "Sort mismatch at argument #" << (i+1)
-                   << " for function " << mk_pp(f,*this)
-                   << " supplied sort is "
-                   << mk_pp(actual_sort, *this);
-            throw ast_exception(buffer.str());
+            throw ast_exception(std::format("Sort mismatch at argument #{} for function {} supplied sort is {}",
+                                             i + 1,
+                                             to_string(mk_pp(f, *this)),
+                                             to_string(mk_pp(actual_sort, *this))));
         }
     }
 }
@@ -2223,12 +2220,13 @@ app * ast_manager::mk_app(func_decl * decl, unsigned num_args, expr * const * ar
                    decl->get_family_id() == basic_family_id && !decl->is_associative());
 
     if (type_error) {
-        std::ostringstream buffer;
-        buffer << "Wrong number of arguments (" << num_args
-               << ") passed to function " << mk_pp(decl, *this) << " ";
+        std::string arg_list;
         for (unsigned i = 0; i < num_args; ++i)
-            buffer << "\narg: " << mk_pp(args[i], *this) << "\n";
-        throw ast_exception(std::move(buffer).str());
+            arg_list += std::format("\narg: {}\n", to_string(mk_pp(args[i], *this)));
+        throw ast_exception(std::format("Wrong number of arguments ({}) passed to function {} {}",
+                                         num_args,
+                                         to_string(mk_pp(decl, *this)),
+                                         arg_list));
     }
     app * r = nullptr;
     if (num_args == 1 && decl->is_chainable() && decl->get_arity() == 2) {
diff --git a/src/ast/ast_pp.h b/src/ast/ast_pp.h
index 1f20ce300..4fb0daef0 100644
--- a/src/ast/ast_pp.h
+++ b/src/ast/ast_pp.h
@@ -71,3 +71,11 @@ inline std::string& operator+=(std::string& s, mk_pp const& pp) {
     return s = s + pp;
 }
 
+// Helper function to convert streamable objects (like mk_pp) to strings for use with std::format
+template<typename T>
+inline std::string to_string(T const& obj) {
+    std::ostringstream strm;
+    strm << obj;
+    return std::move(strm).str();
+}
+