produced the PowerPC CPUs at the time, and potentially stood to benefit from any reputational damage to the Pentium or Intel as a company. However, the decision led to corporate buyers of PC equipment demanding replacements of existing Pentium CPUs, and soon afterwards other PC manufacturers began offering "no questions asked" replacements of flawed Pentium chips. The growing dissatisfaction with Intel's response led to the company offering to replace all flawed Pentium processors on request on December 20. On January 17, 1995, Intel announced "a pre-tax charge of $475 million against earnings, ostensibly the total cost associated with replacement of the flawed processors." This is equivalent to $ in . Intel was criticised for barring resellers and OEMs from participating in the recall program, requiring end-users to replace chips themselves. Intel's justification for this, posted on its support web page, was that "it is the individual decision of the end user to determine if the flaw is affecting their application accuracy". A 1995 article in Science describes the value of number theory problems in discovering computer bugs and gives the mathematical background and history of Brun's constant, the problem Nicely was working on when he discovered the bug. Intel's response to the FDIV bug has been cited as a case of the public relations impact of a problem eclipsing the practical impact of said problem on customers. While most users were unlikely to encounter the flaw in their day-to-day computing, the company's initial reaction to not replace chips unless customers could guarantee they were affected caused pushback from a vocal minority of industry experts. The subsequent publicity generated shook consumer confidence in the CPUs, and led to a demand for action even from people unlikely to be affected by the issue. Andrew Grove, Intel's CEO at the time was quoted in The Wall Street Journal as saying "I think the kernel of the issue we missed ... was that we presumed to tell somebody what they should or shouldn't worry about, or should or shouldn't do". In the aftermath of the bug and subsequent recall, there was a marked increase in the use of formal verification of hardware floating point operations across the semiconductor industry. Prompted by the discovery of the bug, a technique applicable to the SRT algorithm called "word-level model checking" was developed in 1996. Intel went on to use formal verification extensively in the development of later