Solve falsely returns zero for simple expressions containing BigFractions

[HannesWell]

Describe the bug

Symja's Solve function returns result zero for simple expressions if the expression contains fractions whose numerator and denominator are integers exceeding the int value range and are therefore represented by a BigFraction.

To Reproduce

Example input Symja input expression:

>> Solve(x==Sqrt(9810/(2758454771764429/2251799813685248*2*6250796477692329/562949953421312)),x)

Error result:

{{x−>0}}

Expected behavior

The same result as if I were just evaluating the expression by itself.

>> Sqrt(9810/(2758454771764429/2251799813685248*2*6250796477692329/562949953421312))

as symbolic result

1125899906842624* sqrt(1635/5747513123739563366932509455047)

or numeric result

18.9897250155989157898553301222607618072295268142120...

Java

• Version [e.g. Java 11]

Maybe this also relates to #918? But I haven't checked the latest snapshot yet.

[axkr]

I changed isZERO() which uses PossibleZeroQ to isZero().
The main problem is that PossibleZeroQ uses a very weak numerically approx. for comparison.