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4.14.2 number expressions
A number expression is:
-
a rational number (there are NO spaces allowed inside a rational number,
see int expressions)
-
a floating point number (if the coefficient field is
real ):
<digits>. <digits>e <sign><digits>
-
an identifier of type number
-
a function returning number
-
an int expression (see Type conversion and casting)
-
number expressions combined by the arithmetic operations
+ , - , * , / , ^ , or ** .
-
a type cast to number
Example:
| // the following expressions are in any ring int expressions
2 / 3;
==> // ** int division with `/`: use `div` instead in line >> 2 / 3;<<
==> 0
4/ 8;
==> // ** int division with `/`: use `div` instead in line >> 4/ 8;<<
==> 0
2 /2; // the notation of / for div might change in the future
==> // ** int division with `/`: use `div` instead in line >> 2 /2; // the\
notation of / for div might change in the future<<
==> 1
ring r0=0,x,dp;
2/3, 4/8, 2/2 ; // are numbers
==> 2/3 1/2 1
poly f = 2x2 +1;
leadcoef(f);
==> 2
typeof(_);
==> number
ring rr =real,x,dp;
1.7e-2; 1.7e+2; // are valid (but 1.7e2 not), if the field is `real`
==> (1.700e-02)
==> (1.700e+02)
ring rp = (31,t),x,dp;
2/3, 4/8, 2/2 ; // are numbers
==> 11 -15 1
poly g = (3t2 +1)*x2 +1;
leadcoef(g);
==> (3t2+1)
typeof(_);
==> number
par(1);
==> (t)
typeof(_);
==> number
| See
Type conversion and casting;
ring.
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