diff --git a/main.py b/main.py
index e30a1c9..0ba11d4 100644
--- a/main.py
+++ b/main.py
@@ -98,21 +98,22 @@ def cal_loop():
     span_count = 3  # 几个档距
     # n个档距,n-1个直线塔
     h_array = [0, 0, 0]
-    l_array = [300, 400, 500]
+    l_array = [400, 400, 400]
     t_array = [15, 15, 15]
     lambda_array = [lambda_m, lambda_m, lambda_m]
     loop_count = 1
     sigma_0 = sigma_m * 0.8
     while True:
         sigma_0 = sigma_0 + 0.001
-        sigma = [sigma_0, 0, 0]
+        sigma_array = [sigma_0, 0, 0]
         b_i = 0
+        delta_l_i_array = []
         for i in range(span_count - 1):
             h_i = h_array[i]
             l_i = l_array[i]
             lambda_i = lambda_array[i]
             t_i = t_array[i]
-            sigma_i = sigma[i]
+            sigma_i = sigma_array[i]
             _delta_l_i = delta_li(
                 h_i,
                 l_i,
@@ -126,6 +127,7 @@ def cal_loop():
                 t_m,
                 sigma_m,
             )
+            delta_l_i_array.append(_delta_l_i)
             b_i += _delta_l_i
             length_i = string_length
             g_i = string_g
@@ -145,20 +147,75 @@ def cal_loop():
                 l_i1,
                 lambda_i1,
             )
-            sigma[i + 1] = sigma_i1
+            sigma_array[i + 1] = sigma_i1
         # print("第{loop_count}轮求解。".format(loop_count=loop_count))
         # print(b_i)
         loop_count += 1
         if math.fabs(b_i) < 1e-5:
-            print("找到解。")
+            print("迭代{loop_count}次找到解。".format(loop_count=loop_count))
             print("悬垂串偏移累加bi为{b_i}".format(b_i=b_i))
+            for i in range(span_count):
+                print("第{i}档导线应力为{tension}".format(i=i, tension=sigma_array[i]))
+            for i in range(span_count - 1):
+                print("第{i}串偏移值为{bias}".format(i=i, bias=delta_l_i_array[i]))
+            verify(
+                area,
+                h_array,
+                l_array,
+                string_length,
+                string_g,
+                sigma_array,
+                delta_l_i_array,
+                lambda_array,
+            )
             break
         if loop_count >= loop_end:
             print("!!!未找到解。")
-            print(sigma)
+            print(sigma_array)
             print(b_i)
             break
 
 
+# 检验等式。
+def verify(
+    area: float,
+    h_array: [float],
+    l_array: [float],
+    string_length: [float],
+    string_g: [float],
+    sigma_array: [float],
+    delta_l_i_array: [float],
+    lambda_array: [float],
+):
+    # 用新版大手册p329页(5-61)最第一个公式校验
+    for i in range(len(delta_l_i_array)):
+        sigma_i = sigma_array[i]
+        sigma_i1 = sigma_array[i + 1]
+        left_equ = sigma_array[i + 1]
+        _delta_l_i = delta_l_i_array[i]
+        lambda_i = lambda_array[i]
+        lambda_i1 = lambda_array[i + 1]
+        h_i = h_array[i]
+        h_i1 = h_array[i + 1]
+        l_i = l_array[i]
+        l_i1 = l_array[i + 1]
+        beta_i = math.atan(h_i / l_i)
+        beta_i1 = math.atan(h_i1 / l_i1)
+        w_i = (
+            lambda_i * l_i / 2 / math.cos(beta_i)
+            + sigma_i * h_i / l_i
+            + (lambda_i1 * l_i1 / 2 / math.cos(beta_i1) - sigma_i1 * h_i1 / l_i1)
+        )
+        right_equ = sigma_i + delta_l_i_array[i] / math.sqrt(
+            string_length ** 2 - delta_l_i_array[i] ** 2
+        ) * (string_g / 2 / area + w_i)
+        if math.fabs(right_equ - left_equ) > 1e-4:
+            print("!!!等式不满足")
+            return
+    print("等式满足。")
+
+
 cal_loop()
+
+
 print("Finished.")