.theorem {
  display: block;
  width:90%;
  margin:30px auto;
  font-style: italic;
  counter-increment: theorem;
}
.theorem:before {
  content: "Théorème " counter(theorem) ".";
  font-weight: bold;
  font-style: normal;
}
.theorem p:first-child {
  display: inline;
}


.lemma {
  display: block;
  width:90%;
  margin:30px auto;
  font-style: italic;
  counter-increment: lemma;
}
.lemma:before {
  content: "Lemme " counter(lemma) ".";
  font-weight: bold;
  font-style: normal;
}
.lemma p:first-child {
  display: inline;
}

.corollary {
  display: block;
  width:90%;
  margin:30px auto;
  font-style: italic;
  counter-increment: corollary;
}
.corollary:before {
  content: "Corollaire " counter(corollary) ".";
  font-weight: bold;
  font-style: normal;
}
.corollary p:first-child {
  display: inline;
}

.proposition {
  display: block;
  width:90%;
  margin:30px auto;
  font-style: italic;
  counter-increment: proposition;
}
.proposition:before {
  content: "Proposition " counter(proposition) ".";
  font-weight: bold;
  font-style: normal;
}
.proposition p:first-child {
  display: inline;
}

.property {
  display: block;
  width:90%;
  margin:30px auto;
  font-style: italic;
  counter-increment: property;
}
.property:before {
  content: "Propriété " counter(property) ".";
  font-weight: bold;
  font-style: normal;
}
.property p:first-child {
  display: inline;
}

.assumption {
  display: block;
  width:90%;
  margin:30px auto;
  font-style: italic;
  counter-increment: assumption;
}
.assumption:before {
  content: "Hypothèse " counter(assumption) ".";
  font-weight: bold;
  font-style: normal;
}
.assumption p:first-child {
  display: inline;
}

.definition {
  display: block;
  width:90%;
  margin:30px auto;
  font-style: italic;
  counter-increment: definition;
}
.definition:before {
  content: "Définition " counter(definition) ".";
  font-weight: bold;
  font-style: normal;
}
.definition p:first-child {
  display: inline;
}

.proof {
  display: block;
  margin: 30px 0;
  font-style: normal;
}
.proof:before {
  content: "Preuve.";
  font-style: italic;
}
.proof:after {
  content: "\25FC";
  float:right;
  margin-top: -35px;
}
.proof p:first-child {
  display: inline;
}
