diff --git a/examples/example1.qasm b/examples/example1.qasm
index 23e4712..c26ddea 100644
--- a/examples/example1.qasm
+++ b/examples/example1.qasm
@@ -1,31 +1,39 @@
 // This program does nothing in particular, but shows how to use g2q functions.;
 // example1.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[5];
 creg c[5];
 // Five reset gates.;
+// Begin g1y;
 reset q[0];
 reset q[1];
 reset q[2];
 reset q[3];
 reset q[4];
+// End g1y;
 // A swap gate.;
+// Begin swap;
 cx q[0],q[1];
 cx q[1],q[0];
 cx q[0],q[1];
+// End swap;
 // A swap-fast gate.;
 swap q[0],q[1];
 // Five h gates.;
+// Begin g1y;
 h q[0];
 h q[1];
 h q[2];
 h q[3];
 h q[4];
+// End g1y;
 // Two x gates.;
+// Begin g1y;
 x q[1];
 x q[2];
+// End g1y;
 // Various basic gates.;
 id q[3];
 y q[4];
@@ -40,18 +48,23 @@ u3(1.6,1.6,1.6) q[2];
 // Controlled x.;
 cx q[2],q[0];
 // Controlled y.;
+// Begin cy;
 sdg q[4];
 cx q[3],q[4];
 s q[4];
+// End cy;
 // Controlled y in fast form.;
 cy q[3],q[1];
 // Controlled z.;
+// Begin cz;
 h q[2];
 cx q[4],q[2];
 h q[2];
+// End cz;
 // Controlled z in fast form.;
 cz q[4],q[2];
 // Controlled h.;
+// Begin ch;
 h q[0];
 sdg q[0];
 cx q[2],q[0];
@@ -63,9 +76,11 @@ h q[0];
 s q[0];
 x q[0];
 s q[2];
+// End ch;
 // Controlled h in fast form.;
 ch q[2],q[0];
 // Toffoli (ccx).;
+// Begin ccx;
 h q[2];
 cx q[1],q[2];
 tdg q[2];
@@ -81,6 +96,7 @@ cx q[0],q[1];
 t q[0];
 tdg q[1];
 cx q[0],q[1];
+// End ccx;
 // Toffoli in fast form.;
 ccx q[0],q[1],q[2];
 // rx.;
@@ -96,26 +112,32 @@ u1(1.6) q[3];
 // rz in fast form.;
 rz(1.570795) q[3];
 // crz.;
+// Begin crz;
 u1(0.8) q[4];
 cx q[3],q[4];
 u1(-0.8) q[4];
 cx q[3],q[4];
+// End crz;
 // crz in fast form.;
 crz(1.570795) q[3],q[4];
 // Controlled u1.;
+// Begin cu1;
 u1(0.8) q[2];
 cx q[2],q[0];
 u1(-0.8) q[0];
 cx q[2],q[0];
 u1(0.8) q[2];
+// End cu1;
 // Controlled u1 in fast form.;
 cu1(1.6) q[2],q[0];
 // Controlled u3.;
+// Begin cu3;
 u1(0.0) q[0];
 cx q[2],q[0];
 u3(-0.8,0,-1.6) q[0];
 cx q[2],q[0];
 u3(0.8,1.6,0) q[0];
+// End cu3;
 // Controlled u3 in fast form.;
 cu3(1.6,1.6,1.6) q[2],q[0];
 // Conditional1 eq.;
@@ -123,11 +145,13 @@ if(q==1) y q[2];
 // Conditional2 eq.;
 if(q[2]!=1) y q[2];
 // Barriers.;
+// Begin g1y;
 barrier q[0];
 barrier q[1];
 barrier q[2];
 barrier q[3];
 barrier q[4];
+// End g1y;
 // Measuring;
 measure q[0] -> c[0];
 measure q[1] -> c[1];
diff --git a/examples/example10.qasm b/examples/example10.qasm
index e3c60a3..8b223eb 100644
--- a/examples/example10.qasm
+++ b/examples/example10.qasm
@@ -1,23 +1,29 @@
 // example10.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[5];
 creg c[5];
+// Begin g1y;
 h q[0];
 h q[1];
 h q[2];
 h q[3];
 h q[4];
+// End g1y;
+// Begin g1y;
 x q[0];
 x q[1];
 x q[2];
 x q[3];
 x q[4];
+// End g1y;
+// Begin qmeasy;
 measure q[0] -> c[0];
 measure q[1] -> c[1];
 measure q[2] -> c[2];
 measure q[3] -> c[3];
 measure q[4] -> c[4];
+// End qmeasy;
 // qdeclare qx-simulator error_model depolarizing_channel,0.001;
 // qdeclare qlib-simulator // Hello qlib-simulator;
diff --git a/examples/example11.qasm b/examples/example11.qasm
index e3b5bca..dec97ea 100644
--- a/examples/example11.qasm
+++ b/examples/example11.qasm
@@ -1,14 +1,16 @@
 // example11.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[5];
 creg c[5];
 sdg q[0];
+// Begin g1y;
 id q[1];
 id q[2];
 id q[3];
 id q[4];
+// End g1y;
 h q[0];
 sdg q[3];
 h q[3];
@@ -29,10 +31,12 @@ h q[3];
 h q[4];
 cx q[3],q[2];
 h q[3];
+// Begin qmeasy;
 measure q[0] -> c[0];
 measure q[1] -> c[1];
 measure q[2] -> c[2];
 measure q[3] -> c[3];
 measure q[4] -> c[4];
+// End qmeasy;
 // qdeclare qx-simulator error_model depolarizing_channel,0.001;
 // qdeclare qlib-simulator // Hello qlib-simulator;
diff --git a/examples/example12.qasm b/examples/example12.qasm
index ac6072a..16bec31 100644
--- a/examples/example12.qasm
+++ b/examples/example12.qasm
@@ -1,5 +1,5 @@
 // example12.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[3];
@@ -8,6 +8,7 @@ x q[0];
 h q[1];
 h q[2];
 h q[0];
+// Begin ccx;
 h q[0];
 cx q[1],q[0];
 tdg q[0];
@@ -23,6 +24,7 @@ cx q[2],q[1];
 t q[2];
 tdg q[1];
 cx q[2],q[1];
+// End ccx;
 h q[1];
 h q[2];
 x q[1];
@@ -34,7 +36,9 @@ x q[1];
 x q[2];
 h q[1];
 h q[2];
+// Begin qmeasy;
 measure q[1] -> c[1];
 measure q[2] -> c[2];
+// End qmeasy;
 // qdeclare qx-simulator error_model depolarizing_channel,0.001;
 // qdeclare qlib-simulator // Hello qlib-simulator;
diff --git a/examples/example2.qasm b/examples/example2.qasm
index 73965af..64d2d54 100644
--- a/examples/example2.qasm
+++ b/examples/example2.qasm
@@ -1,5 +1,5 @@
 // example2.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[2];
diff --git a/examples/example3.qasm b/examples/example3.qasm
index 6866c9e..d38e4b1 100644
--- a/examples/example3.qasm
+++ b/examples/example3.qasm
@@ -1,29 +1,47 @@
 // example3.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[5];
 creg c[5];
+// Begin g1y;
 h q[0];
 h q[1];
+// End g1y;
+// Begin g1y;
 s q[0];
 s q[1];
+// End g1y;
+// Begin g1cxg1;
 h q[0];
 cx q[1],q[0];
 h q[0];
+// End g1cxg1;
+// Begin g1y;
 s q[0];
 s q[1];
+// End g1y;
+// Begin g1y;
 h q[0];
 h q[1];
+// End g1y;
+// Begin g1y;
 x q[0];
 x q[1];
+// End g1y;
+// Begin g1cxg1;
 h q[0];
 cx q[1],q[0];
 h q[0];
+// End g1cxg1;
+// Begin g1y;
 x q[0];
 x q[1];
+// End g1y;
+// Begin g1y;
 h q[0];
 h q[1];
+// End g1y;
 // Measuring;
 measure q[0] -> c[0];
 measure q[1] -> c[1];
diff --git a/examples/example4.qasm b/examples/example4.qasm
index bcc60df..7cfcf65 100644
--- a/examples/example4.qasm
+++ b/examples/example4.qasm
@@ -1,42 +1,58 @@
 // example4.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[5];
 creg c[5];
+// Begin g1y;
 h q[0];
 h q[1];
 h q[2];
 h q[3];
 h q[4];
+// End g1y;
+// Begin g1xy;
+// Begin g1y;
 id q[0];
 id q[1];
 id q[2];
 id q[3];
 id q[4];
+// End g1y;
+// Begin g1y;
 id q[0];
 id q[1];
 id q[2];
 id q[3];
 id q[4];
+// End g1y;
+// Begin g1y;
 id q[0];
 id q[1];
 id q[2];
 id q[3];
 id q[4];
+// End g1y;
+// Begin g1y;
 id q[0];
 id q[1];
 id q[2];
 id q[3];
 id q[4];
+// End g1y;
+// Begin g1y;
 id q[0];
 id q[1];
 id q[2];
 id q[3];
 id q[4];
+// End g1y;
+// End g1xy;
 // Measuring;
+// Begin qmeasy;
 measure q[0] -> c[0];
 measure q[1] -> c[1];
 measure q[2] -> c[2];
 measure q[3] -> c[3];
 measure q[4] -> c[4];
+// End qmeasy;
diff --git a/examples/example5.qasm b/examples/example5.qasm
index 7e3e3af..476b7ee 100644
--- a/examples/example5.qasm
+++ b/examples/example5.qasm
@@ -1,13 +1,15 @@
 // example5.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[4];
 creg c[2];
+// Begin g1y;
 h q[0];
 h q[1];
 h q[2];
 h q[3];
+// End g1y;
 cx q[0],q[1];
 h q[2];
 h q[0];
diff --git a/examples/example6.qasm b/examples/example6.qasm
index 5de75d1..ea9a59c 100644
--- a/examples/example6.qasm
+++ b/examples/example6.qasm
@@ -1,13 +1,15 @@
 // example6.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[4];
 creg c[2];
+// Begin g1y;
 h q[0];
 h q[1];
 h q[2];
 h q[3];
+// End g1y;
 cx q[0],q[1];
 h q[2];
 h q[0];
diff --git a/examples/example7.qasm b/examples/example7.qasm
index df620d1..7323a79 100644
--- a/examples/example7.qasm
+++ b/examples/example7.qasm
@@ -1,13 +1,15 @@
 // example7.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[4];
 creg c[2];
+// Begin g1y;
 h q[0];
 h q[1];
 h q[2];
 h q[3];
+// End g1y;
 cx q[0],q[1];
 h q[2];
 h q[0];
diff --git a/examples/example8.qasm b/examples/example8.qasm
index 3488d83..8e6746b 100644
--- a/examples/example8.qasm
+++ b/examples/example8.qasm
@@ -1,21 +1,27 @@
 // example8.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[5];
 creg c[5];
+// Begin g1y;
 h q[0];
 h q[1];
 h q[2];
 h q[3];
 h q[4];
+// End g1y;
+// Begin g1y;
 x q[0];
 x q[1];
 x q[2];
 x q[3];
 x q[4];
+// End g1y;
+// Begin qmeasy;
 measure q[0] -> c[0];
 measure q[1] -> c[1];
 measure q[2] -> c[2];
 measure q[3] -> c[3];
 measure q[4] -> c[4];
+// End qmeasy;
diff --git a/examples/example9.qasm b/examples/example9.qasm
index 1696e8a..db846fc 100644
--- a/examples/example9.qasm
+++ b/examples/example9.qasm
@@ -1,21 +1,27 @@
 // example9.qasm;
-// Compiled with g2q - v1.2.3;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[5];
 creg c[5];
+// Begin g1y;
 h q[0];
 h q[1];
 h q[2];
 h q[3];
 h q[4];
+// End g1y;
+// Begin g1y;
 x q[0];
 x q[1];
 x q[2];
 x q[3];
 x q[4];
+// End g1y;
+// Begin qmeasy;
 measure q[0] -> c[0];
 measure q[1] -> c[1];
 measure q[2] -> c[2];
 measure q[3] -> c[3];
 measure q[4] -> c[4];
+// End qmeasy;
diff --git a/g2q0.scm b/g2q0.scm
index 1c69d82..685dd44 100644
--- a/g2q0.scm
+++ b/g2q0.scm
@@ -48,7 +48,8 @@
 	    qcond1
 	    qcond2
 	    qvalid-conditional
-	    swap))
+	    swap
+	    qcomg))
 
 
 ; qhead - Defines program name.
@@ -300,11 +301,25 @@
 ; - https://algassert.com/post/1717
 ;
 (define (swap p_l1 p_y1 p_y2)
-  (display "// swap\n")
+  (qcomg "swap" 0)
   (qcx "cx" p_l1 p_y1 p_l1 p_y2)
   (qcx "cx" p_l1 p_y2 p_l1 p_y1)
   (qcx "cx" p_l1 p_y1 p_l1 p_y2)
-  (display "// end swap\n"))
-
+  (qcomg "swap" 1))
 
 
+; qxomg - Comments for complex gates. Useful to identify various code sections 
+; when complex gates are compiled into QASM2 code.
+;
+; Arguments:
+; - p_s: string (gate name).
+; - p_v: value indicating the kind of gate comment.
+;  - 0: begin block.
+;  - 1: end block.
+;
+(define (qcomg p_s p_v)
+  (let ((s ""))
+    (cond ((eq? p_v 0)(set! s (strings-append (list (g2q-txt 6) "Begin " p_s ";") 0))))
+    (cond ((eq? p_v 1)(set! s (strings-append (list (g2q-txt 6) "End " p_s ";") 0))))
+    (display s)
+    (newline)))
diff --git a/g2q1.scm b/g2q1.scm
index ffffc23..b92e37e 100644
--- a/g2q1.scm
+++ b/g2q1.scm
@@ -43,7 +43,7 @@
 ; g2q-version - Returns the current version of the compiler.
 ;
 (define (g2q-version)
-  (let ((res "g2q - v1.2.3"))
+  (let ((res "g2q - v1.2.4"))
     res))
 
 
@@ -75,7 +75,7 @@
 ; g2q-select-qpu - Select qpu to be used.
 ;
 ; Output:
-; - String containing the name of the selected qpu. DEfaults to qlib_simulator.
+; - String containing the name of the selected qpu. Defaults to qlib_simulator.
 ;
 (define (g2q-select-qpu)
   (let ((res1 3)
diff --git a/g2q2.scm b/g2q2.scm
index 8a6c819..f503145 100644
--- a/g2q2.scm
+++ b/g2q2.scm
@@ -96,13 +96,13 @@
 ; - p_y2: ordinal of the last qubit.
 ;
 (define (g1y p_n1 p_l1 p_y1 p_y2)
-  (display "// g1y\n")
+  (qcomg "g1y" 0)
   (let loop ((i p_y1))
     (if (= i p_y2)
 	(g1 p_n1 p_l1 i)
 	(begin (g1 p_n1 p_l1 i)
 	       (loop (+ i 1)))))
-  (display "// end g1y\n"))
+  (qcomg "g1y" 1))
 
 
 ; g1x - Repeats placement of gate p_n1 and group p_l1 by repeating the use of
@@ -115,13 +115,13 @@
 ; - p_m1: number of iterations.
 ;
 (define (g1x p_n1 p_l1 p_y1 p_m1)
-  (display "// g1x\n")
+  (qcomg "g1x" 0)
   (let loop ((i 1))
     (if (= i p_m1)
 	(g1 p_n1 p_l1 p_y1)
 	(begin (g1 p_n1 p_l1 p_y1)
 	       (loop (+ i 1)))))
-  (display "// end g1x\n"))
+  (qcomg "g1x" 1))
 
 
 ; g1xy - Repeats placement of gate p_n1 and group p_l1 by repeating the use of
@@ -135,13 +135,13 @@
 ; - p_x1: number if iterations that g1y will be repeated along x axis of sequence as a graph.
 ;
 (define (g1xy p_n1 p_l1 p_y1 p_y2 p_x1)
-  (display "// g1xy\n")
+  (qcomg "g1xy" 0)
   (let loop ((j 1))
     (if (= j p_x1)
 	(g1y p_n1 p_l1 p_y1 p_y2)
 	(begin (g1y p_n1 p_l1 p_y1 p_y2)
 	       (loop (+ j 1)))))
-  (display "// end g1xy\n"))
+  (qcomg "g1xy" 1))
 
 
 ; qmeasy - Performs measurements on group p_l1 to group p_l2 from p_y1 to p_y2.
@@ -153,13 +153,13 @@
 ; - p_y2: ordinal of the last qubit.
 ;
 (define (qmeasy p_l1 p_l2 p_y1 p_y2)
-  (display "// qmeasy\n")
+  (qcomg "qmeasy" 0)
   (let loop ((i p_y1))
     (if (= i p_y2)
 	(qmeas p_l1 p_y2 p_l2 p_y2)
 	(begin (qmeas p_l1 i p_l2 i)
 	       (loop (+ i 1)))))
-  (display "// end qmeasy\n"))
+  (qcomg "qmeasy" 1))
 
 
 ; cx - Gate cx.
@@ -183,11 +183,11 @@
 ; - p_y2: target qubit 2.
 ;
 (define (cz p_l1 p_y1 p_l2 p_y2)
-  (display "// cz\n")  
+  (qcomg "cz" 0)
   (g1 "h" p_l1 p_y2)
   (cx p_l1 p_y1 p_l2 p_y2)
   (g1 "h" p_l2 p_y2)
-  (display "// end cz\n"))
+  (qcomg "cz" 1))
 
 
 ; cz-fast - Gate cz, controlled y in fast form.
@@ -211,11 +211,11 @@
 ; - p_y2: target qubit 2.
 ;
 (define (cy p_l1 p_y1 p_l2 p_y2)
-  (display "// cy\n")
+  (qcomg "cy" 0)
   (g1 "sdg" p_l2 p_y2)
   (cx p_l1 p_y1 p_l2 p_y2)
   (g1 "s" p_l2 p_y2)
-  (display "// end cy\n"))
+  (qcomg "cy" 1))
 
 
 ; cy-fast - Gate cy, controlled y in fast form.
@@ -239,7 +239,7 @@
 ; - p_y2: target qubit 2.
 ;
 (define (ch p_l1 p_y1 p_l2 p_y2)
-  (display "// ch\n")
+  (qcomg "ch" 0)
   (g1 "h" p_l2 p_y2)
   (g1 "sdg" p_l2 p_y2)
   (cx p_l1 p_y1 p_l2 p_y2)
@@ -251,7 +251,7 @@
   (g1 "s" p_l2 p_y2)
   (g1 "x" p_l2 p_y2)
   (g1 "s" p_l1 p_y1)
-  (display "// end ch\n"))
+  (qcomg "ch" 1))
 
 
 ; ch-fast - Gate ch, controlled h in fast form.
@@ -282,7 +282,7 @@
 ; - Elementary gates for quantum computation - Barenco, Bennet et al. (1995) - https://arxiv.org/pdf/quant-ph/9503016.pdf
 ;
 (define (ccx p_l1 p_y1 p_l2 p_y2 p_l3 p_y3)
-  (display "// ccx\n")
+  (qcomg "ccx" 0)
   (g1 "h" p_l3 p_y3)
   (cx p_l2 p_y2 p_l3 p_y3)
   (g1 "tdg" p_l3 p_y3)
@@ -298,7 +298,7 @@
   (g1 "t" p_l1 p_y1)
   (g1 "tdg" p_l2 p_y2)
   (cx p_l1 p_y1 p_l2 p_y2)
-  (display "// end ccx\n"))
+  (qcomg "ccx" 1))
 
 
 ; ccx-fast - Toffoli (AND) gate in fast form.
@@ -392,13 +392,13 @@
 ; - p_y2: qubit 2.
 ;
 (define (crz p_la p_l1 p_y1 p_l2 p_y2)
-  (display "// crz\n")
+  (qcomg "crz" 0)
   (let ((la (/ p_la 2)))
     (u1 la p_l2 p_y2)
     (cx p_l1 p_y1 p_l2 p_y2)
     (u1 (* -1.0 la) p_l2 p_y2)
     (cx p_l1 p_y1 p_l2 p_y2))
-  (display "// end crz\n"))
+  (qcomg "crz" 1))
 
 
 ; crz-fast - Gate crz, controlled rz expressed in fast form.
@@ -424,14 +424,14 @@
 ; - p_y2: qubit 2.
 ;
 (define (cu1 p_la p_l1 p_y1 p_l2 p_y2)
-  (display "// cu1\n")
+  (qcomg "cu1" 0)
   (let ((la (* p_la 0.5)))
     (u1 la p_l1 p_y1)
     (cx p_l1 p_y1 p_l2 p_y2)
     (u1 (* -1.0 la) p_l2 p_y2)
     (cx p_l1 p_y1 p_l2 p_y2)
     (u1 la p_l1 p_y1))
-  (display "// end cu1\n"))
+  (qcomg "cu1" 1))
 
 
 ; cu1-fast - Gate cu1, controlled phase rotation expressed in fast form.
@@ -458,13 +458,13 @@
 ; - p_y2: qubit 2.
 ;
 (define (cu3 p_la p_pa p_l1 p_y1 p_l2 p_y2)
-  (display "// cu3\n")
+  (qcomg "cu3" 0)
   (u1 (* (- p_la p_pa) 0.5) p_l2 p_y2)
   (cx p_l1 p_y1 p_l2 p_y2)
   (u3 (* (* p_la 0.5) -1.0) 0 (* (* (+ p_pa p_la) 0.5) -1.0) p_l2 p_y2)
   (cx p_l1 p_y1 p_l2 p_y2)
   (u3 (* p_la 0.5) p_pa 0 p_l2 p_y2)
-  (display "// end cu3\n"))
+  (qcomg "cu3" 1))
 
 
 ; cu3-fast - Gate cu3, controlled U expressed in fast form.
@@ -491,11 +491,11 @@
 ; - p_y2: qubit number 2.
 ;
 (define (g1cxg1 p_n1 p_l1 p_y1 p_y2)
-  (display "// g1cxg1\n")
+  (qcomg "g1cxg1" 0)
   (g1 p_n1 p_l1 p_y2)
   (cx p_l1 p_y1 p_l1 p_y2)
   (g1 p_n1 p_l1 p_y2)
-  (display "// end g1cxg1\n"))
+  (qcomg "g1cxg1" 1))
 
 
 ; qendc - Prints a message stating that compilation has ended.
@@ -617,10 +617,10 @@
 ;  - |1> -> |0>
 ;
 (define (qcnot1 p_l2 p_y2 p_l1 p_y1)
-  (display "// qcnot1\n")  
+  (qcomg "qcnot1" 0) 
   (g1 "x" p_l1 p_y1)
   (cx p_l2 p_y2 p_l1 p_y1)
-  (display "// end qcnot1\n"))
+  (qcomg "qcnot1" 1))
 
 
 ; qxor1 - A qcnot1 based XOR gate expressed atomically.
@@ -643,11 +643,11 @@
 ;  - |10> -> |1>
 ;
 (define (qxor1 p_l1 p_y1 p_l2 p_y2 p_l3 p_y3 p_l4 p_y4)
-  (display "// qxor1\n")  
+  (qcomg "qxor1" 0)
   (qcnot1 p_l2 p_y2 p_l1 p_y1)
   (qcnot1 p_l4 p_y4 p_l3 p_y3)
   (qcnot1 p_l3 p_y3 p_l1 p_y1)
-  (display "// end qxor1\n"))
+  (qcomg "qxor1" 1))
 
 
 ; qfclvr - Find and construct label and value registers.
@@ -747,8 +747,10 @@
   (display (strings-append (list "swap " (qbgna p_l1 p_y1) "," (qbgna p_l1 p_y2) (g2q-txt 2)) 0)))
 
 
-; qftyn - qft for n qubits in the range [p_l1[p_y1] : p_l2[p_y2]].
+; qftyn - Quantum Fourier Transformation for n qubits in the range
+; [p_l1[p_y1] : p_l2[p_y2]].
 ;
+; Arguments:
 ; p_l1: quantum register name 1.
 ; p_y1: qubit 1, min limit of the range.
 ; p_l2: quantum register name 2.
@@ -758,7 +760,7 @@
 ; - https://quantum-computing.ibm.com/support/guides/quantum-algorithms-with-qiskit?page=5cbc5e2d74a4010049e1a2b0#qiskit-implementation
 ;
 (define (qftyn p_l1 p_y1 p_l2 p_y2)
-  (display "// qftyn\n")
+  (qcomg "qftyn" 0)
   (let ((i p_y1)
 	(j 0))
     (while (<= i p_y2)
@@ -768,7 +770,8 @@
 		  (cu1 (/ (qconst "Pi") (expt 2 (- j i))) p_l1 j p_l2 i)
 		  (set! j (+ j 1)))
 	   (set! i (+ i 1))))
-    (display "// end qftyn\n"))
+  (qcomg "qftyn" 1))
+
 
 
 
diff --git a/tests/test1.qasm b/tests/test1.qasm
index b303708..3be6e68 100644
--- a/tests/test1.qasm
+++ b/tests/test1.qasm
@@ -1,5 +1,5 @@
 // test1.qasm;
-// Compiled with g2q - v1.2.0;
+// Compiled with g2q - v1.2.4;
 OPENQASM 2.0;
 include "qelib1.inc";
 qreg q[3];
@@ -13,19 +13,26 @@ t q[2];
 sdg q[0];
 tdg q[1];
 reset q[0];
+// Begin swap;
 cx q[1],q[2];
 cx q[2],q[1];
 cx q[1],q[2];
+// End swap;
 swap q[0],q[1];
 cx q[2],q[0];
+// Begin cy;
 sdg q[1];
 cx q[0],q[1];
 s q[1];
+// End cy;
 cy q[2],q[0];
+// Begin cz;
 h q[1];
 cx q[0],q[1];
 h q[1];
+// End cz;
 cz q[2],q[0];
+// Begin ch;
 h q[1];
 sdg q[1];
 cx q[0],q[1];
@@ -37,22 +44,28 @@ h q[1];
 s q[1];
 x q[1];
 s q[0];
+// End ch;
 ch q[2],q[0];
 u1(1.6) q[0];
 u2(1.6,1.6) q[1];
 u3(1.6,1.6,1.6) q[2];
+// Begin cu1;
 u1(0.8) q[2];
 cx q[2],q[0];
 u1(-0.8) q[0];
 cx q[2],q[0];
 u1(0.8) q[2];
+// End cu1;
 cu1(1.6) q[2],q[1];
+// Begin cu3;
 u1(0.0) q[2];
 cx q[2],q[2];
 u3(-0.8,0,-1.6) q[2];
 cx q[2],q[2];
 u3(0.8,1.6,0) q[2];
+// End cu3;
 cu3(1.6,1.6,1.6) q[2],q[0];
+// Begin ccx;
 h q[2];
 cx q[1],q[2];
 tdg q[2];
@@ -68,6 +81,7 @@ cx q[0],q[1];
 t q[0];
 tdg q[1];
 cx q[0],q[1];
+// End ccx;
 ccx q[0],q[1],q[2];
 u3(1.6,-1.570795,1.570795) q[1];
 rx(1.570795) q[1];
@@ -75,18 +89,50 @@ u3(1.6,0,0) q[2];
 ry(1.570795) q[2];
 u1(1.6) q[3];
 rz(1.570795) q[0];
+// Begin crz;
 u1(0.8) q[2];
 cx q[1],q[2];
 u1(-0.8) q[2];
 cx q[1],q[2];
+// End crz;
 crz(1.570795) q[0],q[1];
 if(q==1) y q[2];
 if(q[2]!=1) y q[2];
+// Begin qftyn;
+h q[0];
+// Begin cu1;
+u1(0.7853975) q[1];
+cx q[1],q[0];
+u1(-0.7853975) q[0];
+cx q[1],q[0];
+u1(0.7853975) q[1];
+// End cu1;
+// Begin cu1;
+u1(0.39269875) q[2];
+cx q[2],q[0];
+u1(-0.39269875) q[0];
+cx q[2],q[0];
+u1(0.39269875) q[2];
+// End cu1;
+h q[1];
+// Begin cu1;
+u1(0.7853975) q[2];
+cx q[2],q[1];
+u1(-0.7853975) q[1];
+cx q[2],q[1];
+u1(0.7853975) q[2];
+// End cu1;
+h q[2];
+// End qftyn;
+// Begin g1y;
 barrier q[0];
 barrier q[1];
 barrier q[2];
+// End g1y;
+// Begin qmeasy;
 measure q[0] -> c[0];
 measure q[1] -> c[1];
 measure q[2] -> c[2];
+// End qmeasy;
 // qdeclare qx-simulator error_model depolarizing_channel,0.001;
 // qdeclare qlib-simulator // Hello qlib-simulator;
diff --git a/tests/test1.scm b/tests/test1.scm
index 924eb99..1c3f72d 100644
--- a/tests/test1.scm
+++ b/tests/test1.scm
@@ -138,6 +138,8 @@
   ; Conditionals.
   (qcond1 "==" q 1)(g1 "y" q 2)
   (qcond2 "!=" q 2 1)(g1 "y" q 2)
+  ; QFT
+  (qftyn q 0 q 2)
   ; Barrier and measure.
   (g1y "barrier" q 0 (- qn 1))  
   (qmeasy p_q p_c p_cnl p_cnh)