What constitutes substantial evidence in the context of a motion to appeal against a finding of substantial evidence?

With respect to the first, it is now settled law that "substantial evidence" is not just any evidence but must be evidence " 'of ponderable legal significance, ... reasonable in nature, credible, and of solid value.' [Citations.]" (Bowers v. Bernards (1984) 150 Cal.App.3d 870, 873, 197 Cal.Rptr. 925.) As the Bowers court put it, the existence of substantial evidence is determined by the appellate court in the following manner: "When a trial court's factual determination is attacked on the ground that there is no substantial evidence to sustain it, the power of an appellate court begins and ends with the determination as to whether, on the entire record, there is substantial evidence, contradicted or uncontradicted, which will support the determination, and when two or more inferences can reasonably be deduced from the facts, a reviewing court is without power to substitute its deductions for those of the trial court. If such substantial evidence be [26 Cal.App.4th 1833] found, it is of no consequence that the trial court believing other evidence, or drawing other reasonable inferences, might have reached a contrary conclusion. [Citations.]" (Id., at pp. 873-874, 197 Cal.Rptr. 925; emphasis added in the original; see also Greenfield v. Insurance, Inc. (1971) 19 Cal.App.3d 803, 810, 97 Cal.Rptr. 164.)