Maple 在添加正约束时会产生错误

Question

我正在x,y,z,t 中的一个简单方程组上测试 Maple 2021：

solve({x = 1, a*z^2 = c*t*x, c*x^2 = a*y*z, d*y^2 = b*t*x, 0 < a, 0 < b, 0 < c, 0 < d}, {t, x, y, z});         

结果看起来正确（对不起格式，这是直接从 Maple 复制粘贴的）：

/[[ /     (1/2)  (1/2)              (1/4)  (1/4)  
           |[[ |    d      c                  c      b       
  PIECEWISE|[[< t = -------------, x = 1, y = -------------, 
           |[[ |     (1/2)  (1/2)              (1/4)  (1/4)  
           \[[ \    a      b                  d      a       

         (3/4)  (1/4)\    /     (1/2)  (1/2)         
        c      d     |    |    d      c              
    z = ------------- >, < t = -------------, x = 1, 
         (3/4)  (1/4)|    |     (1/2)  (1/2)         
        a      b     /    \    a      b              

           (1/4)  (1/4)         (3/4)  (1/4)\ ]  
          c      b             c      d     | ]  
    y = - -------------, z = - ------------- >], 
           (1/4)  (1/4)         (3/4)  (1/4)| ]  
          d      a             a      b     / ]  

                                   ]                 \
                                   ]                 |
    And(0 < a, 0 < b, 0 < c, 0 < d)], [[], otherwise]|
                                   ]                 |
                                   ]                 /

我只想得到正解，所以我添加了这样的约束：

solve({c*x^(2)=a*y*z,d*y^(2)=b*t*x,a*z^(2)=c*t*x,x=1,a>0,b>0,c>0,d>0,x>0,y>0,z>0,t>0},{x,y,z,t});

但是，我得到了一个错误：

错误，排版出现内部错误：-解析： "'_Inert_DELAYLESSTHAN' 不是有效的惰性形式"

感谢您的帮助！

Answer 1

使用 Maple 2021.1，我没有收到这样的错误（在显示结果时）。

我只在下面使用lprint，以便我可以更轻松地将结果粘贴到此处。

restart;

kernelopts(version);

   Maple 2021.1, X86 64 LINUX, May 19 2021, Build ID 1539851

sol:=solve({c*x^(2)=a*y*z,d*y^(2)=b*t*x,
            a*z^(2)=c*t*x, x=1,
            a>0,b>0,c>0,d>0,x>0,y>0,z>0,t>0}, 
           {x,y,z,t}):
lprint(%);

piecewise(And(0 < a,0 < b,0 < c,0 < d,0 < 
d*c^2*b/(c^3*d*a*b^3)^(1/2),0 < 1/a/b
*(c^3*d*a*b^3)^(1/4),0 < 
c*b/(c^3*d*a*b^3)^(1/4),0 <= 
c*b/(c^3*d*a*b^3)^(1/4)),
[{t = d^(1/2)*c^(1/2)/a^(1/2)/b^(1/2), x = 1, 
y = c^(1/4)*b^(1/4)/d^(1/4)/a^(1/
4), z = 1/a^(3/4)/b^(1/4)*c^(3/4)*d^(1/4)}],
And(0 < a,0 < b,0 < c,0 < d,0 < d*c
^2*b/(c^3*d*a*b^3)^(1/2),0 < 1/a/b* 
(c^3*d*a*b^3)^(1/4),0 < c*b/(c^3*d*a*b^3)^(1
/4),1/a/b*(c^3*d*a*b^3)^(1/4) < 
0,c*b/(c^3*d*a*b^3)^(1/4) < 0),[{t = 
d*c^2*b/(c^3*d*a*b^3)^(1/2), x = 1, y = 
c*b/(c^3*d*a*b^3)^(1/4), z = 1/a/b*(c^3*d*a*b^3)^
(1/4)}, {t = d*c^2*b/(c^3*d*a*b^3)^(1/2), x = 1,
y = -c*b/(c^3*d*a*b^3)^(1/4),
z = -1/a/b*(c^3*d*a*b^3)^(1/4)}],
And(0 < a,0 < b,0 < c,0 < d,0 < d*c^2*b/(c^3*d
*a*b^3)^(1/2),1/a/b*(c^3*d*a*b^3)^(1/4) < 
0,c*b/(c^3*d*a*b^3)^(1/4) < 0,c*b/(c^
3*d*a*b^3)^(1/4) <= 0),[{t = 
d^(1/2)*c^(1/2)/a^(1/2)/b^(1/2), x = 1, y = -c^(1/
4)*b^(1/4)/d^(1/4)/a^(1/4), z = 
-1/a^(3/4)/b^(1/4)*c^(3/4)*d^(1/4)}],[])

combine(sol) assuming 
a>0,b>0,c>0,d>0,x>0,y>0,z>0,t>0:
lprint(%);

[{t = (d*c/b/a)^(1/2), x = 1, y = 1/d/a* 
(c*b*d^3*a^3)^(1/4), z = 1/a/b*(c^3*d*a
*b^3)^(1/4)}]