''There is no improper relationship.''

Into those five, carefully chosen, classically Clintonesque words-- delivered to public television's Jim Lehrer in an interview on Wednesday--President Clinton inserted two escape hatches. See if you can spot them.

What remains to be seen is whether this Houdini of nondenial-denials can slip through the tightening web of allegations of perjury, suborning perjury and obstruction of justice that have grown out of Paula Jones's lawsuit charging the President with sexual harassment.

The evidence is not all in, and what's known so far might not be enough to cripple a politician with Clinton's survival skills. But this is clearly not just another ''bimbo eruption.'' Clinton's alleged sexual relationship with Monica Lewinsky, now 24, and his alleged effort to cover it up, have fused the Jones case with the criminal investigation by independent counsel Kenneth W. Starr--and conceivably opened a legal avenue to impeachment.

Lewinsky was a starstruck 21-year-old when the President allegedly commenced an intimate physical relationship with her; she was allegedly pressed to deny the relationship both by Clinton and his friend Vernon Jordan; she subsequently denied it in a sworn affidavit prepared by a lawyer recommended by Jordan, who took her to the lawyer's office in his car; and the allegedly false affidavit was filed Jan. 12 in federal court in an effort to quash a subpoena by Paula Jones's lawyers.

Clinton was referring to Lewinsky when he said ''there is no improper relationship.''

Escape hatch No. 1: By saying that there ''is''--a word he used three times in the interview--no improper relationship, Clinton avoided saying whether there ever was such a relationship. The use of the present tense was noted by the news media, prompting Clinton to use ''was'' in two later interviews.