diff --git a/src/step0_repl.cpp b/src/step0_repl.cpp
index 3861738..80df72e 100644
--- a/src/step0_repl.cpp
+++ b/src/step0_repl.cpp
@@ -3,6 +3,8 @@
 #include <string>   // std::getline
 #include <string_view>
 
+#include "forward.h"
+
 #if 0
 auto read(std::string_view data) -> std::string_view
 {
@@ -41,4 +43,19 @@ auto main() -> int
 
 	return 0;
 }
+
+// Below is needed for compilation
+namespace blaze {
+
+auto read(std::string_view) -> ValuePtr
+{
+	return {};
+}
+
+auto eval(ValuePtr, EnvironmentPtr) -> ValuePtr
+{
+	return {};
+}
+
+} // namespace blaze
 #endif
diff --git a/src/step1_read_print.cpp b/src/step1_read_print.cpp
index 479607d..a09f559 100644
--- a/src/step1_read_print.cpp
+++ b/src/step1_read_print.cpp
@@ -9,35 +9,40 @@
 
 #include "ast.h"
 #include "error.h"
+#include "forward.h"
 #include "lexer.h"
 #include "printer.h"
 #include "reader.h"
 #include "settings.h"
 
 #if 0
-auto read(std::string_view input) -> blaze::ASTNodePtr
+namespace blaze {
+
+auto read(std::string_view input) -> ValuePtr
 {
-	blaze::Lexer lexer(input);
+	Lexer lexer(input);
 	lexer.tokenize();
-	if (blaze::Settings::the().get("dump-lexer") == "1") {
+	if (Settings::the().get("dump-lexer") == "1") {
 		lexer.dump();
 	}
 
-	blaze::Reader reader(std::move(lexer.tokens()));
+	Reader reader(std::move(lexer.tokens()));
 	reader.read();
-	if (blaze::Settings::the().get("dump-reader") == "1") {
+	if (Settings::the().get("dump-reader") == "1") {
 		reader.dump();
 	}
 
 	return reader.node();
 }
 
-auto eval(blaze::ASTNodePtr ast) -> blaze::ASTNodePtr
+auto eval(ValuePtr ast, EnvironmentPtr) -> ValuePtr
 {
 	return ast;
 }
 
-auto print(blaze::ASTNodePtr exp) -> std::string
+} // namespace blaze
+
+auto print(blaze::ValuePtr exp) -> std::string
 {
 	blaze::Printer printer;
 	return printer.print(exp);
@@ -48,7 +53,7 @@ auto rep(std::string_view input) -> void
 	blaze::Error::the().clearErrors();
 	blaze::Error::the().setInput(input);
 
-	print("{}\n", print(eval(read(input))).c_str());
+	print("{}\n", print(blaze::eval(blaze::read(input), nullptr)).c_str());
 }
 
 static auto cleanup(int signal) -> void
diff --git a/src/step2_eval.cpp b/src/step2_eval.cpp
index 2fdd470..0b4bf5b 100644
--- a/src/step2_eval.cpp
+++ b/src/step2_eval.cpp
@@ -8,7 +8,9 @@
 
 #include "ast.h"
 #include "environment.h"
+#include "error.h"
 #include "eval.h"
+#include "forward.h"
 #include "lexer.h"
 #include "printer.h"
 #include "reader.h"
@@ -16,33 +18,38 @@
 #include "settings.h"
 
 #if 0
-auto read(std::string_view input) -> blaze::ASTNodePtr
+static blaze::EnvironmentPtr s_outer_env = blaze::Environment::create();
+
+namespace blaze {
+
+auto read(std::string_view input) -> ValuePtr
 {
-	blaze::Lexer lexer(input);
+	Lexer lexer(input);
 	lexer.tokenize();
-	if (blaze::Settings::the().get("dump-lexer") == "1") {
+	if (Settings::the().get("dump-lexer") == "1") {
 		lexer.dump();
 	}
 
-	blaze::Reader reader(std::move(lexer.tokens()));
+	Reader reader(std::move(lexer.tokens()));
 	reader.read();
-	if (blaze::Settings::the().get("dump-reader") == "1") {
+	if (Settings::the().get("dump-reader") == "1") {
 		reader.dump();
 	}
 
 	return reader.node();
 }
 
-auto eval(blaze::ASTNodePtr ast) -> blaze::ASTNodePtr
+auto eval(ValuePtr ast, EnvironmentPtr env) -> ValuePtr
 {
-	blaze::GlobalEnvironment env;
-	blaze::Eval eval(ast, &env);
+	Eval eval(ast, env);
 	eval.eval();
 
 	return eval.ast();
 }
 
-auto print(blaze::ASTNodePtr exp) -> std::string
+} // namespace blaze
+
+auto print(blaze::ValuePtr exp) -> std::string
 {
 	blaze::Printer printer;
 
@@ -54,7 +61,7 @@ auto rep(std::string_view input) -> std::string
 	blaze::Error::the().clearErrors();
 	blaze::Error::the().setInput(input);
 
-	return print(eval(read(input)));
+	return print(blaze::eval(blaze::read(input), s_outer_env));
 }
 
 static auto cleanup(int signal) -> void
@@ -87,6 +94,8 @@ auto main(int argc, char* argv[]) -> int
 	std::signal(SIGINT, cleanup);
 	std::signal(SIGTERM, cleanup);
 
+	installFunctions(s_outer_env);
+
 	blaze::Readline readline(pretty_print, history_path);
 
 	std::string input;
diff --git a/src/step3_env.cpp b/src/step3_env.cpp
index 0ee7056..0b4bf5b 100644
--- a/src/step3_env.cpp
+++ b/src/step3_env.cpp
@@ -10,6 +10,7 @@
 #include "environment.h"
 #include "error.h"
 #include "eval.h"
+#include "forward.h"
 #include "lexer.h"
 #include "printer.h"
 #include "reader.h"
@@ -17,34 +18,38 @@
 #include "settings.h"
 
 #if 0
-static blaze::EnvironmentPtr env = blaze::makePtr<blaze::GlobalEnvironment>();
+static blaze::EnvironmentPtr s_outer_env = blaze::Environment::create();
 
-auto read(std::string_view input) -> blaze::ASTNodePtr
+namespace blaze {
+
+auto read(std::string_view input) -> ValuePtr
 {
-	blaze::Lexer lexer(input);
+	Lexer lexer(input);
 	lexer.tokenize();
-	if (blaze::Settings::the().get("dump-lexer") == "1") {
+	if (Settings::the().get("dump-lexer") == "1") {
 		lexer.dump();
 	}
 
-	blaze::Reader reader(std::move(lexer.tokens()));
+	Reader reader(std::move(lexer.tokens()));
 	reader.read();
-	if (blaze::Settings::the().get("dump-reader") == "1") {
+	if (Settings::the().get("dump-reader") == "1") {
 		reader.dump();
 	}
 
 	return reader.node();
 }
 
-auto eval(blaze::ASTNodePtr ast) -> blaze::ASTNodePtr
+auto eval(ValuePtr ast, EnvironmentPtr env) -> ValuePtr
 {
-	blaze::Eval eval(ast, env);
+	Eval eval(ast, env);
 	eval.eval();
 
 	return eval.ast();
 }
 
-auto print(blaze::ASTNodePtr exp) -> std::string
+} // namespace blaze
+
+auto print(blaze::ValuePtr exp) -> std::string
 {
 	blaze::Printer printer;
 
@@ -56,7 +61,7 @@ auto rep(std::string_view input) -> std::string
 	blaze::Error::the().clearErrors();
 	blaze::Error::the().setInput(input);
 
-	return print(eval(read(input)));
+	return print(blaze::eval(blaze::read(input), s_outer_env));
 }
 
 static auto cleanup(int signal) -> void
@@ -89,6 +94,8 @@ auto main(int argc, char* argv[]) -> int
 	std::signal(SIGINT, cleanup);
 	std::signal(SIGTERM, cleanup);
 
+	installFunctions(s_outer_env);
+
 	blaze::Readline readline(pretty_print, history_path);
 
 	std::string input;
diff --git a/src/step4_if_fn_do.cpp b/src/step4_if_fn_do.cpp
index 2dfeaca..7af9d70 100644
--- a/src/step4_if_fn_do.cpp
+++ b/src/step4_if_fn_do.cpp
@@ -23,9 +23,7 @@ static blaze::EnvironmentPtr s_outer_env = blaze::Environment::create();
 static auto cleanup(int signal) -> void;
 static auto installLambdas(blaze::EnvironmentPtr env) -> void;
 static auto rep(std::string_view input, blaze::EnvironmentPtr env) -> std::string;
-static auto read(std::string_view input) -> blaze::ASTNodePtr;
-static auto eval(blaze::ASTNodePtr ast, blaze::EnvironmentPtr env) -> blaze::ASTNodePtr;
-static auto print(blaze::ASTNodePtr exp) -> std::string;
+static auto print(blaze::ValuePtr exp) -> std::string;
 
 auto main(int argc, char* argv[]) -> int
 {
@@ -93,35 +91,39 @@ static auto rep(std::string_view input, blaze::EnvironmentPtr env) -> std::strin
 	blaze::Error::the().clearErrors();
 	blaze::Error::the().setInput(input);
 
-	return print(eval(read(input), env));
+	return print(blaze::eval(blaze::read(input), env));
 }
 
-static auto read(std::string_view input) -> blaze::ASTNodePtr
+namespace blaze {
+
+auto read(std::string_view input) -> ValuePtr
 {
-	blaze::Lexer lexer(input);
+	Lexer lexer(input);
 	lexer.tokenize();
-	if (blaze::Settings::the().get("dump-lexer") == "1") {
+	if (Settings::the().get("dump-lexer") == "1") {
 		lexer.dump();
 	}
 
-	blaze::Reader reader(std::move(lexer.tokens()));
+	Reader reader(std::move(lexer.tokens()));
 	reader.read();
-	if (blaze::Settings::the().get("dump-reader") == "1") {
+	if (Settings::the().get("dump-reader") == "1") {
 		reader.dump();
 	}
 
 	return reader.node();
 }
 
-static auto eval(blaze::ASTNodePtr ast, blaze::EnvironmentPtr env) -> blaze::ASTNodePtr
+auto eval(ValuePtr ast, EnvironmentPtr env) -> ValuePtr
 {
-	blaze::Eval eval(ast, env);
+	Eval eval(ast, env);
 	eval.eval();
 
 	return eval.ast();
 }
 
-static auto print(blaze::ASTNodePtr exp) -> std::string
+} // namespace blaze
+
+static auto print(blaze::ValuePtr exp) -> std::string
 {
 	blaze::Printer printer;
 
diff --git a/src/step5_tco.cpp b/src/step5_tco.cpp
index 514afb7..99418d0 100644
--- a/src/step5_tco.cpp
+++ b/src/step5_tco.cpp
@@ -29,9 +29,7 @@ static blaze::EnvironmentPtr s_outer_env = blaze::Environment::create();
 static auto cleanup(int signal) -> void;
 static auto installLambdas(blaze::EnvironmentPtr env) -> void;
 static auto rep(std::string_view input, blaze::EnvironmentPtr env) -> std::string;
-static auto read(std::string_view input) -> blaze::ASTNodePtr;
-static auto eval(blaze::ASTNodePtr ast, blaze::EnvironmentPtr env) -> blaze::ASTNodePtr;
-static auto print(blaze::ASTNodePtr exp) -> std::string;
+static auto print(blaze::ValuePtr exp) -> std::string;
 
 auto main(int argc, char* argv[]) -> int
 {
@@ -99,35 +97,39 @@ static auto rep(std::string_view input, blaze::EnvironmentPtr env) -> std::strin
 	blaze::Error::the().clearErrors();
 	blaze::Error::the().setInput(input);
 
-	return print(eval(read(input), env));
+	return print(blaze::eval(blaze::read(input), env));
 }
 
-static auto read(std::string_view input) -> blaze::ASTNodePtr
+namespace blaze {
+
+auto read(std::string_view input) -> ValuePtr
 {
-	blaze::Lexer lexer(input);
+	Lexer lexer(input);
 	lexer.tokenize();
-	if (blaze::Settings::the().get("dump-lexer") == "1") {
+	if (Settings::the().get("dump-lexer") == "1") {
 		lexer.dump();
 	}
 
-	blaze::Reader reader(std::move(lexer.tokens()));
+	Reader reader(std::move(lexer.tokens()));
 	reader.read();
-	if (blaze::Settings::the().get("dump-reader") == "1") {
+	if (Settings::the().get("dump-reader") == "1") {
 		reader.dump();
 	}
 
 	return reader.node();
 }
 
-static auto eval(blaze::ASTNodePtr ast, blaze::EnvironmentPtr env) -> blaze::ASTNodePtr
+auto eval(ValuePtr ast, EnvironmentPtr env) -> ValuePtr
 {
-	blaze::Eval eval(ast, env);
+	Eval eval(ast, env);
 	eval.eval();
 
 	return eval.ast();
 }
 
-static auto print(blaze::ASTNodePtr exp) -> std::string
+} // namespace blaze
+
+static auto print(blaze::ValuePtr exp) -> std::string
 {
 	blaze::Printer printer;
 
diff --git a/src/step7_quote.cpp b/src/step7_quote.cpp
index 618ef7b..0ee8d5d 100644
--- a/src/step7_quote.cpp
+++ b/src/step7_quote.cpp
@@ -119,7 +119,6 @@ auto main(int argc, char* argv[]) -> int
 	arg_parser.addOption(dump_reader, 'r', "dump-reader", nullptr, nullptr);
 	arg_parser.addOption(pretty_print, 'c', "color", nullptr, nullptr);
 	arg_parser.addOption(history_path, 'h', "history-path", nullptr, nullptr, nullptr, ruc::ArgParser::Required::Yes);
-	// TODO: Add overload for addArgument(std::vector<std::string_view>)
 	arg_parser.addArgument(arguments, "arguments", nullptr, nullptr, ruc::ArgParser::Required::No);
 	arg_parser.parse(argc, argv);
 
diff --git a/src/step8_macros.cpp b/src/step8_macros.cpp
index 819e818..dc296b2 100644
--- a/src/step8_macros.cpp
+++ b/src/step8_macros.cpp
@@ -126,7 +126,6 @@ auto main(int argc, char* argv[]) -> int
 	arg_parser.addOption(dump_reader, 'r', "dump-reader", nullptr, nullptr);
 	arg_parser.addOption(pretty_print, 'c', "color", nullptr, nullptr);
 	arg_parser.addOption(history_path, 'h', "history-path", nullptr, nullptr, nullptr, ruc::ArgParser::Required::Yes);
-	// TODO: Add overload for addArgument(std::vector<std::string_view>)
 	arg_parser.addArgument(arguments, "arguments", nullptr, nullptr, ruc::ArgParser::Required::No);
 	arg_parser.parse(argc, argv);