dreal / dreal3

There is a new version of dReal, available at https://github.com/dreal/dreal4
GNU General Public License v3.0
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probably tanh bug #241

Closed scungao closed 8 years ago

scungao commented 8 years ago

Check the following dr file. It's trying to see if this big function nn is close to tan near the origin. x1 is the only argument. dReal returns delta-sat saying nn can be huge. But it shouldn't be.

var: [0,0.000001] x1; [-1000,1000] nn; ctr: nn = (971257242.67759383 * (tanh((-0.83136651156762431 * x1 + -1.3890441137474736) / 2)) + -568873673.47067046 * (tanh((-0.97920630516730212 * x1 + -1.4402130368144705) / 2)) + 64153179.71628686 * (tanh((-1.1564016556640022 * x1 + -1.4695509763173511) / 2)) + -16554003040.338058 * (tanh((-0.53355710931598743 * x1 + -0.57133099279086241) / 2)) + -68921.193356639618 * (tanh((-2.0026357358830604 * x1 + -1.7438878427151638) / 2)) + 165799511.70313755 * (tanh((0.96422942263162748 * x1 + 0.64680155488885971) / 2)) + -21937186428.772785 * (tanh((0.52006010145545756 * x1 + 0.24484238547781062) / 2)) + -380152434664.20251 * (tanh((-0.020027851642538078 * x1 + -0.0054234686583924463) / 2)) + 252269158230.90063 * (tanh((-0.034771086028482959 * x1 + -0.0024616651694859492) / 2)) + -954688015.67861867 * (tanh((-0.79816358456414238 * x1 + 0.10312566694423919) / 2)) + -27899405.568769213 * (tanh((1.0186852821285755 * x1 + -0.33535493671670408) / 2)) + 6361242994.3647032 * (tanh((-0.13321747950773469 * x1 + 0.070499179490618777) / 2)) + -869154092.6946975 * (tanh((-0.71453016378715839 * x1 + 0.52103802004944) / 2)) + -1484435.2311509394 * (tanh((1.3513857684266568 * x1 + -1.2557126199391506) / 2)) + -12166786093.24052 * (tanh((-0.2247710560525841 * x1 + 0.25381230212476813) / 2)) + -2293780192.4803324 * (tanh((-0.58902903072080126 * x1 + 0.78293955125853065) / 2)) + 0); abs(tan(x1)-nn)>0.1;